A tutorial on C++ Programming

Prof. Erwin M. Globio, MSIT Page 1 of 66
WORKTEXT for
ITEC223
Advance Programming
(With Laboratory Exercises on every
chapter)
By
PROF. ERWIN M. GLOBIO, MSIT

Chapter 1
Introduction to C programming language
C is a general-purpose high-level programming language with features of economy of
expression, modern flow control & data structures, and a rich set of operators. It is not
specialized to any particular area of application, the absence of restrictions and its
generality make it more convenient and effective for many tasks than any other powerful
languages. It is not tied to any particular hardware or system, and therefore it is easy to
write programs that will run without change on any machine that supports C. It is often
called a middle-level computer language because it combines the best elements of high-
level languages with the control and flexibility of assembly language.
Structure of programming in C
Let's start learning by writing a simple program.
 Every C program starts execution form a user defined function called main(). This
function must be present in every C program. Program can have only one main
function.
/*
This is a simple C++ program.
Call this file Sample.cpp.
*/
#include <iostream>
#include <conio.h>
using namespace std;
// A C++ program begins at main().
int main()
{
cout << "C++ is power programming.";
getch();
return 0;
}
Before beginning, let‘s review two terms: source code and object code. Source code
is the human readable form of the program. It is stored in a text file. Object code is the
executable form of the program created by the compiler.
When run, the program displays the following output:
C++ is power programming.
Although Sample.cpp is quite short, it includes several key features that are common
to all C++ programs. Let‘s closely examine each part of the program. The program begins
with the lines.
/*

This is a simple C++ program.
Call this file Sample.cpp.
*/
This is a comment. Like most other programming languages, C++ lets you enter a
remark into a program‘s source code. The contents of a comment are ignored by the
compiler. The purpose of a comment is to describe or explain the operation of a program to
anyone reading its source code. In the case of this comment, it identifies the program. In
more complex programs, you will use comments to help explain what each feature of the
program is for and how it goes about doing its work.
In the case of this comment, it identifies the program. In more complex programs,
you will use comments to help explain what each feature of the program is for and how it
goes about doing its work. In other words, you can use comments to provide a ―play-by-
play‖ description of what your program does.
The next line in the program is
This tells the compiler to use the std namespace; namespaces are a relatively recent
addition to C++. A namespace creates a declarative region in which various program
elements can be placed. Elements declared in one namespace are separate from elements
declared in another. Namespaces help in the organization of large programs. The using
statement informs the compiler that you want to use the std namespace. This is the
namespace in which the entire Standard C++ library is declared. By using the std
namespace, you simplify access to the standard library.
The next line, as the preceding comment indicates, is where program execution begins.
int main()
All C++ programs are composed of one or more functions. As explained earlier, a
function is a subroutine. Every C++ function must have a name, and the only function that
any C++ program must include is the one shown here, called main(). The main() function is
where program execution begins and (most commonly) ends. (Technically speaking, a C++
program begins with a call to main() and, in most cases, ends when main() returns.) The
opening curly brace on the line that follows main() marks the start of the main() function
code.
cout << "C++ is power programming.";
This is a console output statement. It causes the message C++ is power
programming. to be displayed on the screen. It accomplishes this by using the output
operator <<. The << operator causes whatever expression is on its right side to be output
to the device specified on its left side. cout is a predefined identifier that stands for console
output and generally refers to the computer‘s screen. Thus, this statement causes the
message to be output to the screen. Notice that this statement ends with a semicolon. In
fact, all C++ statements end with a semicolon.

The message ―C++ is power programming.‖ is a string. In C++, a string is a
sequence of characters enclosed between double quotes. Strings are used frequently in
C++.
return 0;
This line terminates main() and causes it to return the value 0 to the calling process
(which is typically the operating system). For most operating systems, a return value of 0
signifies that the program is terminating normally. Other values indicate that the program is
terminating because of some error. return is one of C++‘s keywords, and it is used to
return a value from a function. All of your programs should return 0 when they terminate
normally (that is, without error).
Control Statements
Inside a function, execution proceeds from one statement to the next, top to bottom.
It is possible, however, to alter this flow through the use of the various program control
statements supported by C++.
The if Statement:
if(condition) statement;
where condition is an expression that is evaluated to be either true or false. In C++, true is
nonzero and false is zero. If the condition is true, then the statement will execute. If it is
false, then the statement will not execute. For example, the following fragment displays the
phrase 10 is less than 11 on the screen because 10 is less than 11.
if(10 < 11)
cout << "10 is less than 11";
However, consider the following:
if(10 > 11)
cout << "this does not display";
In this case, 10 is not greater than 11, so the cout statement is not executed. Of
course, the operands inside an if statement need not be constants. They can also be
variables. C++ defines a full complement of relational operators that can be used in a
conditional expression. They are shown here:
Operator Meaning
< Less than
<= Less than equal to
> Greater than
>= Greater that equal to
== Equal to
!= Not equal to

Notice that the test for equality is the double equal sign. Here is a program that
illustrates the if
statement:
#include <iostream>
#include <conio.h>
int main()
{
int a, b, c;
a = 2;
b = 3;
if (a < b)
cout << "a is less than bn"; // An if statement
// this won't display anything
if (a == b)
cout << "you won't see thisn";
cout <<"n";
c = b - a; // c now contains 1
cout << "c contains 1n";
if (c>= 0) cout << "c is non-negative n";
if (c < 0) cout << "c is negative n";
getch();
return 0;
}
The output generated by this program is shown here:
a is less than b
c contains -1
c is negative
c contains 1
c is non-negative
The complete form of the if the statement is
if(expression)
statement;
else
statement;
where the targets of the if and else are single statements. The else clause is optional. The
targets of both the if and else can also be blocks of statement. The general forms of the if
using blocks of statements is:

if(expression)
{
statement sequence;
}
else {
statement sequence;
}
If the conditional expression is true, the target of the if will be executed; otherwise,
the target of the else, if it exists, will be executed. At no time will both be executed. The
conditional expression controlling the if may be any type of valid C++ expression that
produces a true or false result.
The following demonstrates the if by playing a simple version of the ―guess the
magic number‖ game. The program generates a random numbers, prompts for your guess,
and prints the message ** Right ** if you guess the magic number. This program also
introduces another C++ library function, called rand( ), which returns a randomly selected
integer value. It requires the <stdlib> header.
#include <iostream>
#include <conio.h>
main()
{
int magic, guess;
magic = rand();
cout << "Enter your guess: ";
cin >> guess;
if (guess == magic)
cout << "*** Right ***";
getch();
return 0;
}
This program uses the ‗if‘ statement to determine whether the user‘s guess matches
the magic number. If it does, the message is printed on the screen.
Modular Programming
As programs grow in size, it becomes important to break them into separate parts
(modules) that communicate with rest of the program through a few well defined interfaces.
If we decompose the program into modules well is we can code each module
independently. Also if change happens we can localize changes to a particular module
without impacting the rest of the programs.
For example, as is their habit, a LCD which we had used in a product went obsolete.
We had a written the hardware abstraction layer for the LCD as a separate module. We

substituted a different LCD, and modified the LCD hardware abstraction module while not
impacting rest of the program.
How to achieve a modular programming in C?
C provides two keywords static and extern that facilitate this. Disciplined coding
practice also aids modularization.
The key is to have a header file for each module. This header file contains
 a comment section about the module
 definition of all constants publicly exposed by the module
 definition of all structures publicly exposed by the module
 all publicly exposed variables defined with extern
 all publicly exposed functions defined with extern
In the header file you should only put definitions of constants, structures, variables and
functions that you want to expose.
As a coding practice prefix all constant, structure, variable and function definitions with
the name of the module. This makes it easy to identify the source of definition in a larger
program with many modules.
The implementation file(s) contains the actual definition of variables and
implementations of the functions defined in the header file.
The implementation file also contains definitions of those variables, structures and
constants that are used only in the implementation file. It also contains definitions and
implementations of helper functions. These should be declared as static to prevent access
from outside. I all find it a good programming practice to prefix all internal names with "_".
Example
Header file for a module named node node.h
/*
Interface for node module
node_var1 is a variable used inside the module
node_do_something() is a function in the module
*/
extern int node_var1;
extern int node_do_something(void);
Implementation file for module named node node.c:
#include "node.h"
int node_var1;

static int _node_var2;
static void _node_helper_function(void){
}
int node_do_something(void){
node_var1 = 2;
_node_var2 =35;
_node_helper_function();
}
The main file which uses module node
#include "node.h"
int main(int argc, char *argv[]){
while(1){
node_do_something();
}
}

COURSE TITLE : ITEC223 – Advance Programming
EXERCISE NUMBER : 1
COURSE TOPIC : Review of Introduction to C Programming language
I. Objectives:
 To learn and understand the basic syntax and script delimeters of C.
 To understand and use C/C++ variables and operators.
II. Part I. Basic Syntax of C++
1. Where does the C++ program begin execution?
_____________________________________________________________________________
_____________________________________________________________________________
2. What is cout?
_____________________________________________________________________________
_____________________________________________________________________________
3. What does #include <iostream> do?
_____________________________________________________________________________
_____________________________________________________________________________
4. What does the if statement do?
_____________________________________________________________________________
_____________________________________________________________________________
5. How is block of code created? What does it do?
_____________________________________________________________________________
_____________________________________________________________________________
6. What is a namespace?
_____________________________________________________________________________
_____________________________________________________________________________
Supplementary Programming (50 points)
1. Write a program that averages the absolute value of five values entered by the user. Display the
result.

Chapter 2 & 3
String Handling Functions
The string handling functions in the standard C++ libraries incorporated from the
standard C libraries do not have a single header file for a source. When declaring a
character array that will hold a null-terminated string, you need to declare it one character
longer than the largest string that it will hold. For example, if you want to declare an array
str that could hold a 10-character string:
char str[11];
Specifying the size as 11 makes room for the null at the end of the string. A string
constant is a list of characters enclosed in double quotes. Here are some examples:
―hello there‖ ―I like C++‖ ―Mars‖ ―‖
It is not necessary to manually add the null terminator onto the end of string
constants; the C++ compiler does this for you automatically. Therefore, the string ―Mars‖
will appear in memory like this:
M a r s 0
The last string shown is "". This is called a null string. It contains only the null
terminator and no other characters. Null strings are useful because they represent the
empty string.
The easiest way to read a string entered from the keyboard is to use a char array in
a cin statement. For example, the following program reads a string entered by the user:
// using cin to read a string from the keyboard
#include <iostream>
int main()
{
char str[80];
cout << ―Enter a string: ―;
cin >> str; // read a string from keyboard <-- read a string using cin
cout << ―Here is your string: ―;
cout << str;
return 0;
}
Here is a sample run:
Enter a string: testing

Here is your string: testing
Although this program is technically correct, it will not always work the way you
expect. To see why, run the program and try entering the string ―This is a test‖. Here is
what you will see:
Enter a string: This is a test
Here is your string: This
When the program redisplays your string, it shows only the word ―This‖, not the
entire sentence. The reason for this is that the C++ I/O system stops reading a string when
the first whitespace character is encountered. Whitespace characters include spaces, tabs,
and newlines.
One way to solve the whitespace problem is to use another of C++‘s library
functions, gets( ). The general form of a call to gets( ) is
gets(array-name);
To read a string, call gets( ) with the name of the array, without any index, as its
argument. Upon return from gets( ), the array will hold the string input from the keyboard.
The gets( ) function will continue to read characters, including whitespace, until you enter a
carriage return. The header used by gets( ) is <cstdio>.
This version of the preceding program uses gets( ) to allow the entry of strings
containing spaces:
//Using gets() to read a string from the keyboard.
#include <iostream>
#include <cstdio>
int main()
{
char str[80];
cout << ―Enter a string: ―;
gets(str); // read a string using gets() //  Read a string using gets().
cout << ―Here is your string‖;
cout << str;
return 0;
}

Notice that in a cout statement, str can be used directly. In general, the name of a
character array that holds a string can be used any place that a string constant can be used.
Keep in mind that neither cin nor gets( ) performs any bounds checking on the array
that receives input. Therefore, if the user enters a string longer than the size of the array,
the array will be overwritten.
Some string Library Functions:
C++ supports a wide range of string manipulation functions. The most common are:
strcpy()
strcat()
strcmp()
srtlen()
The string functions all use the same header, <string>. Let‘s take a look at these
functions now.
strcpy
A call to strcpy( ) takes this general form:
strcpy(to, from);
The strcpy( ) function copies the contents of the string from into to. Remember, the
array that forms to must be large enough to hold the string contained in from. If it isn‘t, the
to array will be overrun, which will probably crash your program.
strcat
A call to strcat( ) takes this form: strcat(s1, s2); The strcat( ) function appends s2 to
the end of s1; s2 is unchanged. You must ensure that s1 is large enough to hold its original
contents and those of s2.
strcmp
A call to strcmp( ) takes this general form:
strcmp(s1, s2);
The strcmp( ) function compares two strings and returns 0 if they are equal. If s1 is
greater than s2 lexicographically (that is, according to dictionary order), then a positive
number is returned; if it is less than s2, a negative number is returned.
The key to using strcmp( ) is to remember that it returns false when the strings
match.

Therefore, you will need to use the !operator if you want something to occur when
the strings are equal. For example, the condition controlling the following if statement is
true when str is equal to ―C++‖:
if(!strcmp(str, "C++")
cout << "str is C++";
strlen
The general form of a call to strlen( ) is
strlen(s);
Example using strlen:
#include <string.h>
#include <iostream>
#include <conio.h>
int main()
{
char aString1[11] = "abcdefghij",
aString2[11] = "tooShort",
aString3[51];
unsigned int len1, len2, len3;
cout << endl << endl;
cout << "Please supply a third string: ";
cin.getline(aString3, 11); // 'n' delimiter assumed
len1 = strlen(aString1);
cout << endl << "String #1: " << aString1 << ", length = "
<< len1 << endl << "String #2: " << aString2
<< ", length = " << len2 << endl << "String #3: "
<< aString3 << ", length = " << len3;
cout << endl << endl;
getch();
return 0;

}
where s is a string. The strlen( ) function returns the length of the string pointed to by s.
A String Function Example:
The following program illustrates the use of all four string functions:
// Demonstrate the string functions.
#include <iostream>
#include <stdio.h>
#include <string.h>
#include <windows.h>
#include <conio.h>
int main()
{
char s1[80],s2[80];
strcpy(s1, "C++");
strcpy(s2, " is power programming.");
cout << "lengths: " << strlen(s1);
cout << ' ' << strlen(s2) << 'n';
if(!strcmp(s1, s2))
cout << "The strings are equaln";
else cout << "not equaln";
strcat(s1, s2);
cout << s1 << 'n';
strcpy(s2, s1);
cout << s1 << " and " << s2 << "n";
if(!strcmp(s1, s2))
cout << "s1 and s2 are now the same.n";
getch();
return 0;
}
Here is the output:
lengths: 3 22
not equal
C++ is power programming.
C++ is power programming. and C++ is power programming.
s1 and s2 are now the same.
Using the Null Terminator

The fact that strings are null-terminated can often be used to simplify various
operations. For example, the following program converts a string to uppercase:
// Convert a string to uppercase
#include <iostream>
#include <string.h>
#include <conio.h>
#include <ctype.h>
#include <windows.h>
int main()
{
char str[80];
int i;
strcpy (str, "this is a test");
for (i=0; str[1]; i++)
str[i] = toupper(str[i]);
cout << str;
getch();
return 0;
}
The output from this program is shown here:
THIS IS A TEST
This program uses the library function toupper(), which returns the uppercase
equivalent of its character argument, to convert each character in the string. The upper()
function uses the header <ctype.h>.
Notice that the test condition of the for loop is simply the array indexed by the
condition variable. The reason this works is that a true value is any non-zero value.
Remember, all character values are non-zero, but the null terminating the string is zero.
Because the null terminator marks the end of the string, the loop stops precisely where it is
supposed to.

Table 1: Character functions in <ctype.h>
Function
Function
Signature
Description
isalnum() int isalnum(int c) Returns a non-zero if c is alphabetic or numeric
isalpha() int isalpha(int c) Returns a non-zero if c is alphabetic
iscntrl() int iscntrl(int c) Returns a non-zero if c is a control character
isdigit() int isdigit(int c) Returns a non-zero if c is a digit, 0 - 9
isgraph() int isgraph(int c) Returns a non-zero if c is a non-blank, but printing character
islower() int islower(int c)
Returns a non-zero if c is a lower case alphabetic character,
i.e. a - z
isprint() int isprint(intc)
Returns a non-zero if c is printable, non-blanks and white
space included
ispunct() int ispunct(int c)
Returns a non-zero if c is a printable character, but not alpha,
numeric, or blank
isspace() int isspace(int c)
Returns a non-zero for blanks and these escape sequences:
'f', 'n', 'r', 't', and 'v'
isupper() int isupper(int c)
Returns a non-zero if c is an upper-case alphabetic character,
i.e. A - Z
isxdigit() int isxdigit(int c)
Returns a non-zero if c is a hexadecimal character: 0 - 9, a -
f, or A - F
tolower() int tolower(int c)
Returns the lower case version if c is an upper case character;
otherwise returns c
toupper() int toupper(int c)
Returns the upper case version if c is a lower case character;
otherwise returns c
Table 2: Some String Handling Functions in <string.h>
Functions Function Signature Description
strcat()
char* strcat(char* s1,
const char* s2)
Adds string s2 onto the end of s1 (conCATenation).
strchr()
char* strchr(const char*
s, int c)
Returns a pointer to the first occurrence of c in
string s. Returns NULL if c is not found in s.
strcmp()
int strcmp(const char*
s1, const char* s2)
Compares s1 and s2 alphabetically. Returns a
negative, zero, or positive number depending on
whether s1 is before, the same as, or after s2 if you
were alphabetizing s1 and s2.
strcpy()
char* strcpy(char* s1,
const char* s2)
Copies s2 into s1, and returns a point to s1.
strlen()
size_t strlen(const char*
s)
Returns the number of characters in the string s,
starting at s[0] and ending before the first NULL.
strncat()
char* strncat(char* s1,
const char* s2, size_t n)
Tacks on the first n characters of s2 onto s1. A
pointer to s1 is returned.

strncmp()
int strncmp(const char*
s1, const char* s2, size_t
n)
Compares s1 with the first n characters of s2.
Returns a negative, zero, or positive integer (just like
strcmp).
strncpy()
char* strncpy(char* s1,
const char*s2, size_t n)
Copies the first n characters of s2 into the first n
characters of s1.
strrchr()
char* strrchr(const
char*s, int c)
Returns a pointer to the last occurence of c in string
s. (Compare with strchr().)
strstr()
char* strstr(const char*
s1, const char* s2)
Returns the address of the first occurence of string s2
that is also in string s1. Returns NULL if s2 is not
found in s1.

EXERCISE NUMBER : 2
COURSE TOPIC : String and Handling Function
I. Objectives: To know the String handling function used
Part II. String Handling Functions 1 & 2
1. What is a null-terminated string?
_____________________________________________________________________________
_____________________________________________________________________________
2. To hold a string that is 18 characters long, how must the character array be?
_____________________________________________________________________________
_____________________________________________________________________________
3. Show how to initialize a four-element array of int to the values 1,2,3 and 4.
_____________________________________________________________________________
_____________________________________________________________________________
4. How can this initialization be rewritten?
char str[6] = {‘H’, ‘e’, ‘l’, ‘l’, ‘o’, ‘O’);
_____________________________________________________________________________
_____________________________________________________________________________
5. Rewrite the following as an unsized array:
Int nums[4] = {44, 55, 66, 77}
_____________________________________________________________________________
_____________________________________________________________________________
1. Write a program that prompts the user for two strings and then compares the strings for equality,
but ignores case differences. Thus, “ok” and “OK” will compare as equal.

Chapter 4
Introduction to Pointers
A pointer is an object that contains a memory address. Very often this address is the
location of another object, such as a variable. For example, if x contains the address of y,
then x is said to ―point to‖ y.
Pointer variables must be declared as such. The general form of a pointer variable
declaration is
type *var-name;
Here, type is the pointer‘s base type. The base type determines what type of data
the pointer will be pointing to. var-name is the name of the pointer variable. For example,
to declare ip to be a pointer to an int, use this declaration:
int *ip;
Since the base type of ip is int, it can be used to point to int values. Here, a float
pointer is declared:
float *fp;
In this case, the base type of fp is float, which means that it can be used to point to
a float value.
In general, in a declaration statement, preceding a variable name with an * causes
that variable to become a pointer.
The Pointer Operator
There are two special operators that are used with pointers: * and &. The & is a
unary operator that returns the memory address of its operand.
For example,
ptr = &total;
puts into ptr the memory address of the variable total. This address is the location of
total in the computer‘s internal memory. It has nothing to do with the value of total. The
operation of & can be remembered as returning ―the address of‖ the variable it precedes.
Therefore, the preceding assignment statement could be verbalized as ―ptr receives the
address of total.‖ To better understand this assignment, assume that the variable total is
located at address 100. Then, after the assignment takes place, ptr has the value 100. The
second operator is *, and it is the complement of &. It is a unary operator that returns the
value of the variable located at the address specified by its operand. Continuing with the
same example, if ptr contains the memory address of the variable total, then

val = *ptr;
will place the value of total into val. For example, if total originally had the value
3,200, then val will have the value 3,200, because that is the value stored at location 100,
the memory address that was assigned to ptr. The operation of * can be remembered as ―at
address.‖ In this case, then, the statement could be read as ―val receives the value at
address ptr.‖
The following program executes the sequence of the operations just described:
#include <iostream>
int main()
{
int total;
int *ptr;
int val;
total = 3200; // assign 3,200 to total
ptr = &total; // get address of total
val = *ptr; // get value at that address
cout << "Total is: " << val << 'n';
return 0;
}
It is unfortunate that the multiplication symbol and the ―at address‖ symbol are the
same. This fact sometimes confuses newcomers to the C++ language. These operators
have no relationship to each other. Keep in mind that both & and * have a higher
precedence than any of the arithmetic operators except the unary minus, with which they
have equal precedence. The act of using a pointer is often called indirection because you are
accessing one variable indirectly through another variable.
The Base Type of a Pointer
In the preceding discussion, you saw that it was possible to assign val the value of
total indirectly through a pointer. At this point, you may have thought of this important
question: How does C++ know how many bytes to copy into val from the address pointed
to by ptr? Or, more generally, how does the compiler transfer the proper number of bytes
for any assignment involving a pointer? The answer is that the base type of the pointer
determines the type of data upon which the pointer operates. In this case, because ptr is an
int pointer, four bytes of information are copied into val (assuming a 32-bit int) from the
address pointed to by ptr. However, if ptr had been a double pointer, for example, then
eight bytes would have been copied.
It is important to ensure that pointer variables always point to the correct type of
data. For example, when you declare a pointer to be of type int, the compiler assumes that
anything it points to will be an integer variable. If it doesn‘t point to an integer variable,
then trouble is usually not far behind! For example, the following fragment is incorrect:
int *p; double f; // ... p = &f; // ERROR

This fragment is invalid because you cannot assign a double pointer to an integer
pointer. That is, &f generates a pointer to a double, but p is a pointer to an int. These two
types are not compatible. (In fact, the compiler would flag an error at this point and not
compile your program.) Although two pointers must have compatible types in order for one
to be assigned to another, you can override this restriction (at your own risk) using a cast.
For example, the following fragment is now technically correct:
int *p ; double f; // ... p = (int *) &f; // Now technically OK
The cast to int * causes the double pointer to be converted to an integer pointer.
However, to use a cast for this purpose is questionable practice. The reason is that the base
type of a pointer determines how the compiler treats the data it points to. In this case, even
though p is actually pointing to a floating-point value, the compiler still ―thinks‖ that p is
pointing to an int (because p is an int pointer).
To better understand why using a cast to assign one type of pointer to another is not
usually a good idea, consider the following short program:
//This program will not work right
#include <iostream>
int main()
{
double x,y;
int *p;
x = 123.23;
p = (int *) &x; // use cast to assign double * to int *.
y = *p; // what will this do?
cout << y; // what will this print?
return 0;
Here is the output produced by the program. (You might see a different value.)
1.37439e+009
This value is clearly not 123.23! Here is why. In the program, p (which is an integer
pointer) has been assigned the address of x (which is a double). Thus, when y is assigned
the value pointed to by p, y receives only four bytes of data (and not the eight required for
a double value), because p is an integer pointer. Therefore, the cout statement displays not
123.23, but a garbage value instead.
Assigning value to pointers
You can use a pointer on the left-hand side of an assignment statement to assign a
value to the location pointed to by the pointer. Assuming that p is an int pointer, this
assigns the value 101 to the location pointed to by p.
*p = 101;

You can verbalize this assignment like this: ―At the location pointed to by p, assign
the value 101.‖ To increment or decrement the value at the location pointed to by a pointer,
you can use a statement like this:
(*p)++;
The parentheses are necessary because the * operator has lower precedence than
does the ++ operator.
The following program demonstrates an assignment through a pointer:
#include <iostream>
int main()
{
int *p, num;
p = &num;
*p = 100; // assign num the value 100 through p.
cout << num << ‗ ‗;
(*p)++; // increment num through p.
cout << num << ‗ ‗;
(*p)--; // decrement num through p.
cout << num << ‗/n‘;
return 0;
}
The output from the program is shown here:
100 101 100
Pointer Expressions
Pointers can be used in most C++ expressions. However, some special rules apply.
Remember also that you may need to surround some parts of a pointer expression with
parentheses in order to ensure that the outcome is what you desire.
Pointer Arithmetic There are only four arithmetic operators that can be used on
pointers: ++, – –, +, and –. To understand what occurs in pointer arithmetic, let p1 be an
int pointer with a current value of 2,000 (that is, it contains the address 2,000). Assuming
32-bit integers, after the expression
p1++;
The contents of p1 will be 2,004, not 2,001. The reason for this is that each time p1
is incremented; it will point to the next int. The same is true of decrements. For example,
again assuming that p1 has the value 2000, the expression

p1--;
causes p1 to have the value 1996.
Generalizing from the preceding example, the following rules apply to pointer
arithmetic. Each time that a pointer is incremented, it will point to the memory location of
the next element of its base type. Each time it is decremented, it will point to the location of
the previous element of its base type. In the case of character pointers, an increment or
decrement will appear as ―normal‖ arithmetic because characters are one byte long.
However, every other type of pointer will increase or decrease by the length of its base
type. You are not limited to only increment and decrement operations. You can also add or
subtract integers to or from pointers. The expression
p1 = p1 + 9;
makes p1 point to the ninth element of p1‘s base type, beyond the one to which it is
currently pointing.
Although you cannot add pointers, you can subtract one pointer from another
(provided they are both of the same base type). The remainder will be the number of
elements of the base type that separate the two pointers.
Other than addition and subtraction of a pointer and an integer, or the subtraction of
two pointers, no other arithmetic operations can be performed on pointers. For example,
you cannot add or subtract float or double values to or from pointers.
To graphically see the effects of pointer arithmetic, execute the next short program.
It creates an int pointer (i) and a double pointer (f). It then adds the values 0 through 9 to
these pointers and displays the results. Observe how each address changes, relative to its
base type, each time the loop is repeated. (For most 32-bit compilers, i will increase by 4s
and f will increase by 8s.) Notice that when using a pointer in a cout statement, its address
is automatically displayed in the addressing format applicable to the CPU and environment.
#include <iostream>
int main()
{
int *I, j[10];
double *f, g[10];
int x;
i = j;
f = g;
for (x=0; x<10; x++)
cout << i+x << ‗ ‗ << f+x << ‗n‘; // display the addresses produced by adding x
to each pointer
Here is a sample run. (The precise values you see may differ from these.)
0012FE5C 09012FE84

0012FE60 0012FE8C
0012FE64 0012FE94
0012FE68 0012FE9C
0012FE6C 0012FEA4
0012FE70 0012FEAC
0012FE74 0012FEB4
0012FE78 0012FEBC
0012FE7C 0012FEC4
0012FE80 0012FECC
Pointer Comparisons
Pointers may be compared using the relational operators, such as ==, <, and >. In
general, for the outcome of a pointer comparison to be meaningful, the two pointers must
have some relationship to each other. For example, both may point to elements within the
same array. There is, however, one other type of pointer comparison: any pointer can be
compared to the null pointer, which is zero.

I. Objectives: To identify the use of Pointers in C and its use.
II. Basic Information / Scenario:
Answer the following, using Pointers.
1. What is a pointer?
_____________________________________________________________________________
_____________________________________________________________________________
2. Show how to declare a long int pointer called valPtr.
_____________________________________________________________________________
_____________________________________________________________________________
3. As they relate to pointers, what do the * and & operators do?
_____________________________________________________________________________
_____________________________________________________________________________
4. All pointer arithmetic is performed relative to the _____ of the pointer.
_____________________________________________________________________________
_____________________________________________________________________________
6. Assuming the double is 8 bytes long, when a double pointer is incremented, by how much is its
value increased?
_____________________________________________________________________________
_____________________________________________________________________________
7. What are two pointer operators?
_____________________________________________________________________________
_____________________________________________________________________________

Chapter 5
Pointers and Arrays
In C++, there is a close relationship between pointers and arrays. In fact, frequently
a pointer and an array are interchangeable. Consider this fragment:
char str[80]; char *p1;
p1 = str;
Here, str is an array of 80 characters and p1 is a character pointer. However, it is the
third line that is of interest. In this line, p1 is assigned the address of the first element in
the str array. (That is, after the assignment, p1 will point to str[0].) Here‘s why: In C++,
using the name of an array without an index generates a pointer to the first element in the
array. Thus, the assignment
p1 = str;
assigns the address of str[0] to p1. This is a crucial point to understand: When an
unindexed
array name is used in an expression, it yields a pointer to the first element in the
array. Since, after the assignment, p1 points to the beginning of str, you can use p1 to
access
elements in the array. For example, if you want to access the fifth element in str,
you can use
str[4]
or
*(p1+4)
Both statements obtain the fifth element. Remember, array indices start at zero, so
when str is indexed, a 4 is used to access the fifth element. A 4 is also added to the pointer
p1 to get the fifth element, because p1 currently points to the first element of str.
The parentheses surrounding p1+4 are necessary because the * operation has a
higher priority than the + operation. Without them, the expression would first find the value
pointed to by p1 (the first location in the array) and then add 4 to it. In effect, C++ allows
two methods of accessing array elements: pointer arithmetic and array indexing. This is
important because pointer arithmetic can sometimes be faster than array indexing—
especially when you are accessing an array in strictly sequential order. Since speed is often
a consideration in programming, the use of pointers to access array elements is very
common in C++ programs. Also, you can sometimes write tighter code by using pointers
instead of array indexing.
Here is an example that demonstrates the difference between using array indexing
and pointer arithmetic to access the elements of an array. We will create two versions of a
program that reverse the case of letters within a string. The first version uses array
indexing. The second uses pointer arithmetic. The first version is shown here:
// Reverse case using array indexing.

#include <iostream>
#include <ctype.h>
int main()
{
int i;
char str[80] = "This Is A Test";
cout << "Original string: " << str << "n";
for(i = 0; str[i]; i++)
{
if(isupper(str[i])) str[i] = tolower(str[i]);
else if(islower(str[i])) str[i] = toupper(str[i]);
}
cout << "Inverted-case string: " << str;
return 0;
}
The output from the program is shown here:
Original string: This Is A Test Inverted-case string: tHIS iS a tEST
Notice that the program uses the isupper( ) and islower( ) library functions to
determine the case of a letter. The isupper( ) function returns true when its argument is an
uppercase letter; islower( ) returns true when its argument is a lowercase letter. Inside the
for loop, str is indexed, and the case of each letter is checked and changed. The loop
iterates until the null terminating str is indexed. Since a null is zero (false), the loop stops.
Here is the same program rewritten to use pointer arithmetic:
// Reverse case using array indexing.
#include <iostream>
#include <ctype.h>
int main()
{
int i;
char str[80]; = ―This Is A Test‖;
cout << ―Original string: ― << str << ―n‖;
for i = 0; str[i]; i++) {
if (iupper(str[i]))
else if (islower(str[i]))
str[i] = toupper(str[i]; }
cout << ―Inverted-case string: ― << str;
return 0;
}

In this version, p is set to the start of str. Then, inside the while loop, the letter at p
is checked and changed, and then p is incremented. The loop stops when p points to the
null terminator that ends str. Because of the way some C++ compilers generate code, these
two programs may not be equivalent in performance. Generally, it takes more machine
instructions to index an array than it does to perform arithmetic on a pointer. Consequently,
in professionally written C++ code, it is common to see the pointer version used more
frequently. However, as a beginning C++ programmer, feel free to use array indexing until
you are comfortable with pointers.
Indexing a Pointer
As you have just seen, it is possible to access an array using pointer arithmetic.
What you might find surprising is that the reverse is also true. In C++, it is possible to
index a pointer as if it were an array. Here is an example. It is a third version of the case-
changing program.
//index a pointer as if it were an array.
#include <iostream>
#include <ctype.h>
main()
{
char *p;
int i;
char str[80]=‖This is A Test‖;
cout << ―Original string: ― << str << ―n‖;
p = str; // assign the p address of the start of the array
// now index p
for (I = 0; p[i]; i++)
if (isupper(p[i]))
p[i] = tolower{p[i]);
else if (islower(p[i])
p[i] = toupper(p[i]);
}
cout << ―Inverted – case string:‖ < str;
return 0;
}
The program creates a char pointer called p and then assigns to that pointer the
address of the first element in str. Inside the for loop, p is indexed using the normal array
indexing syntax. This is perfectly valid because in C++, the statement p[i] is function
functionally identical to *(p+i). This further illustrates the close relationship between
pointers and arrays.

EXERCISE NUMBER : 4
COURSE TOPIC : Pointers and Arrays
I. Objectives: To identify the use of Pointers and Arrays using C.
II. Tasks / Procedure / Instructions: Answer the following questions.
1. Can an array be accessed through a pointer?
_____________________________________________________________________________
_____________________________________________________________________________
2. Can a pointer be indexed as if it were an array?
_____________________________________________________________________________
_____________________________________________________________________________
3. An array name used by itself, with no index, yields what?
_____________________________________________________________________________
_____________________________________________________________________________
4. All pointer arithmetic is performed relative to the _____ of the pointer.
_____________________________________________________________________________
_____________________________________________________________________________
5. Assuming the double is 8 bytes long, when a double pointer is incremented, by how much is its
value increased?
_____________________________________________________________________________
_____________________________________________________________________________

Chapter 6
Pointers and String
Strings and Constants
You might be wondering how string constants, like the one in the fragment shown
here, are handled by C++:
cout << strlen("Xanadu");
The answer is that when the compiler encounters a string constant, it stores it in the
program‘s string table and generates a pointer to the string. Thus, ―Xanadu‖ yields a pointer
to its entry in the string table. Therefore, the following program is perfectly valid and prints
the phrase Pointers add power to C++.:
#include <iostream>
int main()
{
char *ptr;
ptr = ―Pointers add power to C++. n‖; // ptr is assigned the address of this string
constant
cout << ptr;
return 0;
}
In this program, the characters that make up a string constant are stored in the
string table, and ptr is assigned a pointer to the string in that table.
Since a pointer into your program‘s string table is generated automatically whenever
a string constant is used, you might be tempted to use this fact to modify the contents of
the string table. However, this is usually not a good idea because many C++ compilers
create optimized tables in which one string constant may be used at two or more different
places in your program. Thus, changing a string may cause undesired side effects.
Reversing a String in Place
Earlier it was mentioned that comparing one pointer to another is meaningful only if
the two pointers point to a common object, such as an array. Now that you understand how
pointers and arrays relate, you can apply pointer comparisons to streamline some types of
algorithms. In this project, you will see an example. The program developed here reverses
the contents of a string, in place. Thus, instead of copying the string back-to-front into
another array, it reverses the contents of the string inside the array that holds it. The
program uses two pointer variables to accomplish this. One initially points to the beginning
of a string, and the other initially points to the last character in the string. A loop is set up
that continues to run as long as the start pointer is less than the end pointer. Each time
through the loop, the characters pointed to by the pointers are swapped and the pointers
are advanced. When the start pointer is greater than or equal to the end pointer, the string
has been reversed.
Step by step

1. Create a file called StrRev.cpp.
2. Begin by adding these lines to the file:
/*
Reverse a string in place.
*/
#include <iostream>
#include <string.h>
int main()
{
char str[ ] = ―this is a test‖;
char *start, *end;
int len;
char t;
The string to be reversed is contained in str. The pointers start and end will be used
to access the string.
3. Add these lines, which display the original string, obtain the string‘s length, and set
the initial values for the start and end pointers:
cout << ―Original: ― << str << ―n‖;
len = str(str);
start = str;end=&str[len-1];
Notice that end points to the last character in the string, not the null terminator.
4. Add the code that reverse the string:
while (start < end) {
// swap chars
t = *starts;
*starts = *end;
*end = t;
// advance pointers
starts++;
end--;
}
The process works like this. As long as the start pointer points to a memory
location that is less than the end pointer, the loop iterates. Inside the loop, the
characters being pointed to by start and end are swapped. Then start is incremented
and end is decremented. When end is greater than or equal to start, all of the
characters in the string have been reversed. Since both start and end point into the
same array, their comparison is meaningful.
5. Here is the complete StrRev.cpp program:

/*
Reverse a string in place.
*/
#include <iostream>
#include <string.h>
int main()
{
char str[ ] = ―this is a test‖;
char *start, *end;
int len;
char t;
cout << ―Original: ― << str << ―n‖;
len = str(str);
start = str;end=&str[len-1];
while (start < end) {
// swap chars
t = *starts;
*starts = *end;
*end = t;
// advance pointers
starts++;
end--;
}
The output from the program is shown here: Original: this is a test Reversed:
tset a si siht
Arrays of Pointers
Pointers can be arrayed like any other data type. For example, declaration for an int
pointer array of size 10 is
int *p[10];
Here, pi is an array of ten integer pointers. To assign the address of an int variable
called var to the third element of the pointer array, you would write
int var;
fpi[2] = &var;

Remember, pi is an array of int pointers. The only thing that the array elements can
hold are the addresses of integer values—not the values themselves. To find the value of
var, you would write
*pi[2]
Like other arrays, arrays of pointers can be initialized. A common use for initialized
pointer arrays is to hold pointers to strings. Here is an example that uses a two-dimensional
array of character pointers to implement a small dictionary:
Here is a sample run:
Enter word: network
An interconnected group of computers.
When the array dictionary is created, it is initialized with a set of words and their
meanings. Recall, C++ stores all string constants in the string table associated with your
program, so the array need only store pointers to the strings. The program works by testing
the word entered by the user against the strings stored in the dictionary. If a match is
found, the meaning is displayed. If no match is found, an error message is printed. Notice

that dictionary ends with two null strings. These mark the end of the array. Recall that a
null string contains only the terminating null character. The for loop runs until the first
character in a string is null. This condition is tested with this expression:
*dictionary[i][0]
The array indices specify a pointer to a string. The * obtains the character at that
location. If this character is null, then the expression is false and the loop terminates.
Otherwise, the expression is true and the loop continues.
The Null Pointer Convention
After a pointer is declared, but before it has been assigned, it will contain an
arbitrary value. Should you try to use the pointer prior to giving it a value, you will probably
crash your program. While there is no sure way to avoid using an uninitialized pointer, C++
programmers have adopted a procedure that helps prevent some errors. By convention, if a
pointer contains the null (zero) value, it is assumed to point to nothing. Thus, if all unused
pointers are given the null value and you avoid the use of a null pointer, you can avoid the
accidental misuse of an uninitialized pointer. This is a good practice to follow.
Any type of pointer can be initialized to null when it is declared. For example, the
following initializes p to null:
float *p = 0; // p is now a null pointer
To check for a null pointer, use an if statement, like one of these:
if(p) // succeeds if p is not null
if(!p) // succeeds if p is null
Multiple Indirection
A pointer to a pointer is a form of multiple indirection, or a chain of pointers.
Consider Figure 4-2. As you can see, in the case of a normal pointer, the value of the
pointer is the address of a value. In the case of a pointer to a pointer, the first pointer
contains the address of the second pointer, which points to the location that contains the
desired value. Multiple indirection can be carried on to whatever extent desired, but there
are few cases where more than a pointer to a pointer is needed, or, indeed, even wise to
use. Excessive indirection is difficult to follow and prone to conceptual errors.

EXERCISE NUMBER : 5
COURSE TOPIC : Pointers and String
I. Objectives: To know how is Pointers and String worked using C.
II. Tasks / Procedure / Instructions: Asnwer the following question.
1. What is it called when one pointer points to another pointer?
_____________________________________________________________________________
_____________________________________________________________________________
2. Of what significant is a null pointer in C++?
_____________________________________________________________________________
_____________________________________________________________________________
1. Write a program that counts the uppercase letters in a string. Have it display the result.

Chapter 7
Structures in Arrays, Functions and Pointers
What is a Structure?
Structure is a collection of variables under a single name. Variables can be of any
type: int, float, char etc. The main difference between structure and array is that arrays are
collections of the same data type and structure is a collection of variables under a single
name.
Declaring a Structure:
The structure is declared by using the keyword struct followed by structure name,
also called a tag. Then the structure members (variables) are defined with their type and
variable names inside the open and close braces { and }. Finally, the closed braces end with
a semicolon denoted as ; following the statement. The above structure declaration is also
called a Structure Specifier.
Example:
Three variables: custnum of type int, salary of type int, commission of type float
are structuremembers and the structure name is Customer. This structure is declared as
follows:
In the above example, it is seen that variables of different types such as int and float are
grouped in a single structure name Customer.
Arrays behave in the same way, declaring structures does not mean that memory is
allocated. Structure declaration gives a skeleton or template for the structure.
After declaring the structure, the next step is to define a structure variable.

How to declare Structure Variable?
This is similar to variable declaration. For variable declaration, data type is defined followed
by variable name. For structure variable declaration, the data type is the name of
the structure followed by thestructure variable name.
In the above example, structure variable cust1 is defined as:
What happens when this is defined? When structure is defined, it allocates or reserves space
in memory. The memory space allocated will be cumulative of all
defined structure members. In the above example, there are 3 structure members:
custnum, salary and commission. Of these, two are of type int and one is of type float.
If integer space allocated by a system is 2 bytes and float four bytes the above would
allocate 2bytes for custnum, 2 bytes for salary and 4 bytes for commission.
How to access structure members in C++?
To access structure members, the operator used is the dot operator denoted by (.). The
dot operatorfor accessing structure members is used thusly:
structure variable name.member name
For example:
To assign 2000 for the structure member salary in the above example of structure
Customer with structure variable cust1 this is written as:

CHAPTER 8
Pointers to structures
All that we have discussed so far has been OK but runs into problems when structures have
to be moved between functions for the following reasons.
 if the structure is large it is more efficient to pass a pointer to the structure instead
of the structure its self. This techniquepri is also used to pass pointers to
arrays between functions.
 When passing a structure to a function, you actually pass a COPY of the structure.
Therefore it is not possible to change the values of members within the structure as
the copy is destroyed when the function ends.
Here is an example. (these are 2 examples, the one to the left uses a pointer)
|
|
struct x {int a; int b; int c;} ; | struct x {int a; int b; int c;} ;
|
void function(struct x); | void function(struct x *);
|
main() | main()
{ | {
struct x z; | struct x z, *pz; /* 3 */
| pz = &z; /* 4 */
z.a = 10; /* 1 */ | z.a = 10;
z.a++; | z.a++;
|
function(z); /* 2 */ | function(pz); /* 5 */
} | }
|
void function( struct x z) | void function(struct x * pz)
{ | { /* 6 */
printf(" first member %d n", z.a); | printf(" first member %d n", (*pz).a);
} | }
|
Here is the annotation.
1. Give a structure member a value.
2. Pass a COPY of the whole structure to the function.
3. Define 'pz' a pointer to a structure of type 'x'.
4. Put the address of 'z' into 'pz'. 'pz' now POINTS to 'z'. PLEASE NOTE. 'z' is defined to
reserve memory equal to the size of the structure. 'pz' only holds an address so will
be 4 bytes long.
5. Pass the pointer into the function.
6. Print the value of the member 'a'.
The (*pz).a syntax is used a great deal in C and it was decided to create a short hand for
it. So:
(*pz).a == pz->a

CHAPTER 9
Structures and Arrays
#include <iostream>
#include <fstream.h>
#include <string.h>
ofstream outData;
//input file structure
ifstream inData;
char menu_id[10];
char menu_name[10];
char menu_col[10];
char menu_row[10];
char button_id[10];
char button_label_1[10];
char button_col[10];
char button_row[10];
//menu file structure
struct menu
{
int mid;
char name[20];
int mcol;
int mrow;
int bid;
char blabel[24];
int bcol;
int brow;
};
//List of menus
enum menu_id
{
MAIN = 1
};
//Define Main menu
menu Main_menu[3];
void createMenu(menu newMenu[], int menu_num,
MAS_Configure_Button_Request_Message*msg )

int y = 0;
while ((!inData.getline(menu_id,10, '$').eof()) && (atoi(menu_id) == menu_num))
{
newMenu[y].mid= atoi(menu_id);
inData.getline(menu_name, 10, '$');
newMenu[y].name[0] = '0';
strcpy(newMenu[y].name,menu_name);
outData << " Main Menu Name " << newMenu[y].name << " " ;
inData.getline( menu_col, 10, '$');
newMenu[y].mcol = atoi(menu_col);
inData.getline( menu_row, 10, '$');
newMenu[y].mrow = atoi(menu_row);
inData.getline( button_id, 10, '$');
newMenu[y].bid = atoi(button_id);
inData.getline( button_label_1, 10, '$');
newMenu[y].blabel[0] = '0';
strcpy(newMenu[y].blabel,button_label_1);
strcat(newMenu[y].blabel,button_label_2);
strcat(newMenu[y].blabel,button_label_3);
outData << newMenu[y].blabel << "; " ;
inData.getline( button_col ,10, '$');
newMenu[y].bcol = atoi(button_col);
inData.getline( button_row ,10, 'n');
newMenu[y].brow = atoi(button_row);
y++;
}
}
int main()
{
int loop;
inData.open("data.txt");
if (!inData)
{
cout << "*** Problem with opening data.txt. End program***" << endl;
return(1);
}

outData.open("test.txt");
if (!outData)
{
cout << "*** Problem with opening test.txt. End program***" << endl;
return(2);
}
createMenu(Main_menu, MAIN, msg);
for (loop = 0; loop < 3; loop ++)
{
outData << " Main menu" << Main_menu[loop].bid << endl;
outData << " Main menu" << Main_menu[loop].blabel << endl;
}
inData.close();
outData.close();
return 0;
}
CHAPTER EXERCISES
Example1: A Simple use of structures
Here‘s a program that uses a struct variable to manage the records in the given file.
Andy DeGeneres Math 98
Gail Stevens English 100
Lia Jacobs Science 99
# include <iostream.h>
struct record
{
char fname[10];
char lname[10];
char subject[10];
int grades;
};
record stud; //record has become like a variable that we can use to define the stud variable
char n1[10];
char n2[10];
char s[10];
int gr;
main()
{
//this is how you assign a value to struct elements
record.fname = ―Andy‖;

record.lname = ―DeGeneres‖;
record.subject = ―Math‖;
record.grade = 98;
//this is how you assign an inputted value to struct elements
cout<<‖Enter a First Name‖;
cin>>n1;
cout<<‖Enter a Last Name‖;
cin>>n2;
cout<<‖Enter a subject‖;
cin>>s;
cout<<‖Enter a grade‖;
cin>>gr;
record.fname = n1;
record.lname = n2;
record.subject = s;
record.grade = gr;
//this is how you retrieve values from a struct
cout<‖ntStudent 1:‖;
cout<<‖nt FnamettLnamettSubjectttGrade‖;
cout<<‖nt‖<<record.fname<<‖tt‖ <<record.lname;
cout<<‖tt‖ <<record.subject<<‖tt‖ <<record.grade‖;
}
******************End of Example 1***********************
Example2: Stuctures, Pointers and Functions
struct x {int a; int b; int c;} ; /* Declare the structure. */
void function(struct x * ); /* the function prototype */
main()
{
/* Declare two variables.
* z == type struct x
* pz == a pointer to type struct x
*/
struct x z, *pz;
pz = &z; /* put the address of 'z' into 'pz' */
z.a = 10; /* initialize z.a */
z.a++; /* Increment z.a */
/* print the contents of 'z.a'
* using the pointer 'pz' */
printf(" first member before the function call %d n", pz->a);

/* Call 'function' passing the
* pointer 'pz' */
function(pz);
/* Print the NEW value of 'z.a'
* using three different notations */
printf(" first member after the function call %d n", pz->a);
printf(" first member after the function call %d n", (*pz).a);
printf(" first member after the function call %d n", z.a);
}
void function(struct x * pz)
{
/* Print the value of 'z.a' by
* referencing the pointer 'pz'
* which holds the address of 'z' */
printf(" first member inside the function %d n", pz->a);
/* Increment the value of 'z.a'
* this is the source location
* in memory. */
pz->a++;
}
*********************End of Example 2***************************
Example 3: Arrays and Structures
#include <iostream.h>
/* Declare a structure. It MUST
* be declared before use.
*/
struct record_format
{
char name[20];
int age;
};
main ()
{
int count=0;
struct record_format record[]=
{
{"Joe Brown", 21},
{"James Dean", 34},
{"David Williams", 54},
{"Neil Harrison", 62},
{"EOF", -1}
};
/*

* Print the contents of the structure.
*/
while( record[count].age != -1)
{
cout<<"name is %s tage is %d n", record[count].name, record[count].age;
count++;
}
}
/************************************************************************
*
* Program will produce:
*
* name is Joe Brown age is 21
* name is James Dean age is 34
* name is David Williams age is 54
* name is Neil Harrison age is 62
*
*************************************************************************
/
*************************End of Example 3************************
CHAPTER QUIZ
COURSE TOPIC : Applying Structures in Functions, Pointers and Arrays
III. Objectives:
 To learn and understand how to declare a structure.

 To understand and use structures with the previously learned constructs, particularly
pointers, functions and arrays
IV. Tasks / Procedure / Instructions:
Part I. Declaration of Structures in Functions, Pointers and Arrays
7. What is the syntax in declaring a structure?
_____________________________________________________________________________
_____________________________________________________________________________
__________
8. What is the use of the dot (.) operator?
_____________________________________________________________________________
_____________________________________________________________________________
__________
9. How do you display the content a structure element? (you may use an example to answer this)
_____________________________________________________________________________
_____________________________________________________________________________
__________
10. How do you declare an array of structures?
_____________________________________________________________________________
_____________________________________________________________________________
__________
11. What is a member?
_____________________________________________________________________________
_____________________________________________________________________________
__________
12. True or False. A structure, once declared, is used similarly to variables. Show an example.
_____________________________________________________________________________
_____________________________________________________________________________
_______
2. Write a program that defines a structure to add two fractions together.
CHAPTER 10
File Handling
What is a File?

Abstractly, a file is a collection of bytes stored on a secondary storage device, which
is generally a disk of some kind. The collection of bytes may be interpreted, for example, as
characters, words, lines, paragraphs and pages from a textual document; fields and records
belonging to a database; or pixels from a graphical image. The meaning attached to a
particular file is determined entirely by the data structures and operations used by a
program to process the file. It is conceivable (and it sometimes happens) that a graphics file
will be read and displayed by a program designed to process textual data. The result is that
no meaningful output occurs (probably) and this is to be expected. A file is simply a
machine decipherable storage media where programs and data are stored for machine
usage.
Essentially there are two kinds of files that programmers deal with text files and
binary files. These two classes of files will be discussed in the following sections.
ASCII Text files
A text file can be a stream of characters that a computer can process sequentially. It
is not only processed sequentially but only in forward direction. For this reason a text file is
usually opened for only one kind of operation (reading, writing, or appending) at any given
time.
Similarly, since text files only process characters, they can only read or write data
one character at a time. (In C Programming Language, Functions are provided that deal
with lines of text, but these still essentially process data one character at a time.) A text
stream in C is a special kind of file. Depending on the requirements of the operating system,
newline characters may be converted to or from carriage-return/linefeed combinations
depending on whether data is being written to, or read from, the file. Other character
conversions may also occur to satisfy the storage requirements of the operating system.
These translations occur transparently and they occur because the programmer has
signalled the intention to process a text file.
Binary files
A binary file is no different to a text file. It is a collection of bytes. In C Programming
Language a byte and a character are equivalent. Hence a binary file is also referred to as a
character stream, but there are two essential differences.
1. No special processing of the data occurs and each byte of data is transferred to or
from the disk unprocessed.
2. C Programming Language places no constructs on the file, and it may be read from,
or written to, in any manner chosen by the programmer.
Binary files can be either processed sequentially or, depending on the needs of the
application, they can be processed using random access techniques. In C Programming
Language, processing a file using random access techniques involves moving the current file
position to an appropriate place in the file before reading or writing data. This indicates a
second characteristic of binary files is that they are generally processed using read and
write operations simultaneously.
For example, a database file will be created and processed as a binary file. A record
update operation will involve locating the appropriate record, reading the record into
memory, modifying it in some way, and finally writing the record back to disk at its

appropriate location in the file. These kinds of operations are common to many binary files,
but are rarely found in applications that process text files.
Creating a file and output some data
In order to create files we have to learn about File I/O i.e. how to write data into a
file and how to read data from a file. We will start this section with an example of writing
data to a file. We begin as before with the include statement for stdio.h, then define some
variables for use in the example including a rather strange looking new type.
EXAMPLE:
/* Program to create a file and write some data the file */
#include <stdio.h>
#include <stdio.h>
main( )
{
FILE *fp;
char stuff[25];
int index;
fp = fopen("TENLINES.TXT","w"); /* open for writing */
strcpy(stuff,"This is an example line.");
for (index = 1; index <= 10; index++)
fprintf(fp,"%s Line number %dn", stuff, index);
fclose(fp); /* close the file before ending program */
}
The type FILE is used for a file variable and is defined in the stdio.h file. It is used to define
a file pointer for use in file operations. Before we can write to a file, we must open it. What
this really means is that we must tell the system that we want to write to a file and what
the file name is. We do this with the fopen() function illustrated in the first line of the
program. The file pointer, fp in our case, points to the file and two arguments are required
in the parentheses, the file name first, followed by the file type.
The file name is any valid DOS file name, and can be expressed in upper or lower case
letters, or even mixed if you so desire. It is enclosed in double quotes. For this example we
have chosen the name TENLINES.TXT. This file should not exist on your disk at this time. If
you have a file with this name, you should change its name or move it because when we
execute this program, its contents will be erased. If you don‘t have a file by this name, that
is good because we will create one and put some data into it. You are permitted to include a
directory with the file name.The directory must, of course, be a valid directory otherwise an
error will occur. Also, because of the way C handles literal strings, the directory separation
character must be written twice. For example, if the file is to be stored in the PROJECTS
sub directory then the file name should be entered as ―PROJECTSTENLINES.TXT‖. The
second parameter is the file attribute and can be any of three letters, r, w, or a, and must
be lower case.
Reading (r)
When an r is used, the file is opened for reading, a w is used to indicate a file to be
used for writing, and an a indicates that you desire to append additional data to the data
already in an existing file. Most C compilers have other file attributes available; check your

Reference Manual for details. Using the r indicates that the file is assumed to be a text file.
Opening a file for reading requires that the file already exist. If it does not exist, the file
pointer will be set to NULL and can be checked by the program.
EXAMPLE:
Here is a small program that reads a file and display its contents on screen.
/* Program to display the contents of a file on screen */
#include <stdio.h>
void main()
{
FILE *fopen(), *fp;
int c;
fp = fopen("prog.c","r");
c = getc(fp) ;
while (c!= EOF)
{
putchar(c);
c = getc(fp);
}
fclose(fp);
}
Writing (w)
When a file is opened for writing, it will be created if it does not already exist and it
will be reset if it does, resulting in the deletion of any data already there. Using the w
indicates that the file is assumed to be a text file.
EXAMPLE:
Here is the program to create a file and write some data into the file.
#include <stdio.h>
int main()
{
FILE *fp;
file = fopen("file.txt","w");
/*Create a file and add text*/
fprintf(fp,"%s","This is just an example :)"); /*writes data to the file*/
fclose(fp); /*done!*/
return 0;
}
Appending (a)
When a file is opened for appending, it will be created if it does not already exist and
it will be initially empty. If it does exist, the data input point will be positioned at the end of

the present data so that any new data will be added to any data that already exists in the
file. Using the a indicates that the file is assumed to be a text file.
Here is a program that will add text to a file which already exists and there is some text in
the file.
#include <stdio.h>
int main()
{
FILE *fp
file = fopen("file.txt","a");
fprintf(fp,"%s","This is just an example :)"); /*append some text*/
fclose(fp);
return 0;
}
Outputting to the file
The job of actually outputting to the file is nearly identical to the outputting we have
already done to the standard output device. The only real differences are the new function
names and the addition of the file pointer as one of the function arguments. In the example
program, fprintf replaces our familiar printf function name, and the file pointer defined
earlier is the first argument within the parentheses. The remainder of the statement looks
like, and in fact is identical to, the printf statement.
Closing a file
To close a file you simply use the function fclose with the file pointer in the
parentheses. Actually, in this simple program, it is not necessary to close the file because
the system will close all open files before returning to DOS, but it is good programming
practice for you to close all files in spite of the fact that they will be closed automatically,
because that would act as a reminder to you of what files are open at the end of each
program.
You can open a file for writing, close it, and reopen it for reading, then close it, and
open it again for appending, etc. Each time you open it, you could use the same file pointer,
or you could use a different one. The file pointer is simply a tool that you use to point to a
file and you decide what file it will point to. Compile and run this program. When you run it,
you will not get any output to the monitor because it doesnâ€™t generate any. After
running it, look at your directory for a file named TENLINES.TXT and type it; that is where
your output will be. Compare the output with that specified in the program; they should
agree! Do not erase the file named TENLINES.TXT yet; we will use it in
some of the other examples in this section.
Reading from a text file
Now for our first program that reads from a file. This program begins with the
familiar include, some data definitions, and the file opening statement which should require
no explanation except for the fact that an r is used here because we want to read it.
#include <stdio.h>

main( )
{
FILE *fp;
char c;
funny = fopen("TENLINES.TXT", "r");
if (fp == NULL)
printf("File doesn't existn");
else {
do {
c = getc(fp); /* get one character from the file
*/
putchar(c); /* display it on the monitor
*/
} while (c != EOF); /* repeat until EOF (end of file)
*/
}
fclose(fp);
}
In this program we check to see that the file exists, and if it does, we execute the main
body of the program. If it doesn‘t, we print a message and quit. If the file does not exist,
the system will set the pointer equal to NULL which we can test. The main body of the
program is one do while loop in which a single character is read from the file and output to
the monitor until an EOF (end of file) is detected from the input file. The file is then closed
and the program is terminated. At this point, we have the potential for one of the most
common and most perplexing problems of programming in C. The variable returned from
the getc function is a character, so we can use a char variable for this purpose. There is a
problem that could develop here if we happened to use an unsigned char however, because
C usually returns a minus one for an EOF – which an unsigned char type variable is not
capable of containing. An unsigned char type variable can only have the values of zero to
255, so it will return a 255 for a minus one in C. This is a very frustrating problem to try to
find. The program can never find the EOF and will therefore never terminate the loop. This
is easy to prevent: always have a char or int type variable for use in returning an EOF.
There is another problem with this program but we will worry about it when we get to the
next program and solve it with the one following that.
After you compile and run this program and are satisfied with the results, it would be a good
exercise to change the name of TENLINES.TXT and run the program again to see that the
NULL test actually works as stated. Be sure to change the name back because we are still
not finished with TENLINES.TXT.
File Handling
In C++ we say data flows as streams into and out of programs. There are different kinds of
streams of data flow for input and output. Each stream is associated with a class, which
contains member functions and definitions for dealing with that particular kind of flow. For
example, the if stream class represents the input disc files,. Thus each file in C++ is an
object of a particular stream class.
CHAPTER EXERCISE
FILE HANDLING: READ,WRITE, APPEND to a FILE

EXAMPLE 1: Program to create a file and write some data the file
#include <stdio.h>
#include <stdio.h>
main( )
{
FILE *fp;
char stuff[25];
int index;
fp = fopen("TENLINES.TXT","w"); /* open for writing */
strcpy(stuff,"This is an example line.");
for (index = 1; index <= 10; index++)
fprintf(fp,"%s Line number %dn", stuff, index);
fclose(fp); /* close the file before ending program */
}
Example 2. A program that reads a file and display its contents on screen.
/* Program to display the contents of a file on screen */
#include <stdio.h>
void main()
{
FILE *fopen(), *fp;
int c;
fp = fopen("prog.c","r");
c = getc(fp) ;
while (c!= EOF)
{
putchar(c);
c = getc(fp);
}
fclose(fp);
}
Example 3: A program to create a file and write some data into the file.
#include <stdio.h>
int main()
{
FILE *fp;
file = fopen("file.txt","w");
/*Create a file and add text*/
fprintf(fp,"%s","This is just an example :)"); /*writes data to the file*/
fclose(fp); /*done!*/
return 0;

}

CHAPTER QUIZ
COURSE TOPIC : File Handling
V. Objectives:
 To learn and understand how to manage external files, particularly, .txt formats.
 To create, write to, read from and append to files using c++ constructs.
VI. Tasks / Procedure / Instructions:
Part I. Declaration of Structures in Functions, Pointers and Arrays
1. What is a file?
_____________________________________________________________________________
_____________________________________________________________________________
__________
3. When do we use the r command?
_____________________________________________________________________________
_____________________________________________________________________________
__________
4. TRUE Or FALSE? When you open a file for appending, a new one will be created if the file is
not yet existing.
_____________________________________________________________________________
_____________________________________________________________________________
__________
5. Write a program that will count characters in a file. Prompt the user for file and the count the
number of characters and lines in it.
Sample Output:
** The program must prompt the user to enter another file if the file entered
cannot be opened.
CHAPTER 11
Enter Filename:
There are <n> characters in < filename>
There are <n> lines.

Introduction to Visual C++
Visual C++ comes within Microsoft Visual Studio. Visual Studio also contains Visual Basic,
Visual C#, and Visual J#. Using Visual Studio, you can mix and match languages within one
"solution". We will, however, focus on developing C++ code throughout these labs.
For your first C++ program, you will build a console mode application that displays a
greeting message. This (i.e. a console mode application) is the kind of VC++ programs that
you will build for all your lab and class exercises/assignments.
Console mode programs are often simpler to build than Windows applications, and this
example will take you through the steps of creating, building and executing a program in
Visual C++. We first assume that you use the built-in code editor in Visual Studio to edit
your code; then we will show you how to build and run your C++ programs that you have
created with any external editors.
1.1.1 How to start
Press on your window desktop, choose All Programs from the popup menu, then
choose Microsoft Visual Studio , and Microsoft Visual Studio
1.1.2 Starting Your First Program
Select Visual C++ Development Settings, then click on Start Visual Studio. Note: If
you want to choose another environment later, click on Tools menu -> Import and
Export ->Reset all Settings ->Next, then you can pick either save current settings or
overwrite current settings.
The next thing you will see is the Start Page.
To get started on your first program, you must create a "project" that will keep track
of all the parts of your program, including the C++ source code, the header files, etc.
Therefore, click the "Create Project" link. A "New Project" dialogue box similar to the
one below will appear.

Follow these steps:
 For a "Name:", type a project name ("hello")
 "Location:", you can leave it in default location D:VS2008
 Note: files created on D drive will not be deleted unless the user do so.
 Click on "OK"
The "Win32 Application Wizard" will appear. As demonstrated below, click on "Application
Settings" and select "Empty Project".

After this, click on "Finish". You will notice that it doesn't appear like anything has
changed (you still see the "Start Page"). However, look at the "Solution Explorer" on the
left-hand side you will see "Solution 'hello' (1 project)".
You want to add C++ source code to this project.
Select Project --> Add New Item... from the main menu, and select C++ File
(.cpp) from the "Templates" section on the right-hand side. Type in the file name:
"hello.cpp" in the Name:box. Click on "Add". This file will be added to the hello work space
that we have just created, and a blank document will be opened for editing
EXERCISE:
Type this code in the code window
// FILE: hello.cpp
// PURPOSE: An example of a simple I/O stream
#include <iostream>
int main()
{
char name[50];
cout << "Please enter your name:" << endl;
cin >> name;
cout << "Hello, " << name << endl;
return 0;
}
SAVE it as Hello.cpp.
Building the hello Project
In order to compile any code in Visual C++, you have to create a project. A project holds
three major types of information:
1) It remembers all of the source code files that combine together to create one executable.
In this simple example, the file hello.cpp will be the only source file, but in larger
applications you often break the code up into several different files to make it easier to
understand (and also to make it possible for several people to work on it simultaneously).
The project maintains a list of the different source files and compiles all of them as
necessary each time you want to create a new executable.
2) It remembers compiler and linker options particular to this specific application. For
example, it remembers which libraries to link into the executable, whether or not you want
to use pre-compiled headers, and so on.
3) It remembers what type of project you wish to build: a console application, a windows
application, etc.

If you are familiar with makefiles, then it is easy to think of a project as a machine-
generated makefile that has a very easy-to-understand user interface to manipulate it. For
now we will create a very simple project file and use it to compile hello.cpp.
1. Compile the hello project by selecting Build --> Compile from the main menu.
It simply compiles the source file and forms the object file (hello.obj) for it. It does not
perform a link, so it is useful only for quickly compiling a file to check for errors.
2. Select Build --> Build hello from the menu bar to link the program.
It compiles all of the source files in the project that have been modified since the last build,
and then links them to create an executable.
3. Choose Debug --> to run the program. A DOS window
will popup.
If errors or warnings are displayed in the Build status window, there is probably an error in
the source file. Check your source file again for missing semicolons, quotes, or braces.
Now, we will continue using Visual C++ in another project, so select File --> Close
Solution. This will return you to the Start Page.
How to compile, link and execute a program with multiple files?
The preceding section showed the procedure for creating a C++ program with only one file
component: hello.cpp, and we used the built-in VC++ source code editor to edit the file.
However, when you are working on a large program, you would break your program into
smaller, more manageable parts. In other words, your project would contain more than one
C++ source files. Moreover, you might not have used the VC++ source code editor to edit
your files.
The following section demonstrates how to create, compile, and execute a VC++ project
with more than one file.
Exercise:
1.2.1 Creating the project
Step 1. Select File --> New --> Project....
Step 2. Set the project name to lab1.
Step 3. Pick a project location, for example D:VS2008
Step 4. Click on "OK" to create the project.
Step 5. Under "Application Settings", select "Empty project".
Step 6. Click on "Finish".
You have now created a project that has information stored in the following folder:
D:VS2008lab1
You can get to this folder through the "Workarea" icon on the desktop.

It is always a good practice to put the source files in this folder. Let's do that now
Get multiple files using anonymous FTP
Obtain the files you need for this lab by clicking here: CS Dept FTP Server
 Right click on these files and save them to your project folder;
1. date.h
2. date.cpp
3. main.cpp
The three files are now copied so the next step is to place them in a folder on your
PC.
 Move your cursor over your local system D:VS2008lab1 folder and right-click.
 Select the Paste option in the resultant pop-up menu.
Even though the files are in the appropriate directory, you must tell Visual Studio that these
files are part of the project.
Adding existing files to the project
1. Select Project --> Add Existing Item....
2. You should be looking in the lab1 directory. Highlight the .h and .cpp files: date.cpp,
date.h and main.cpp
3. Select "Add" to add the files to the project.
To view the contents of any of these files, double click on the file name in the "Solution
Explorer".
Compile, build and execute your progam
1. Select Build --> Build lab1 (This will compile and link the files).
2. Select Debug --> Start Without Debugging
CHAPTER EXERCISE
Example : Small program for beginners demonstrating the use of loops and iostream + iomanip
libraries.
// Program to make a pyramid of characters based on input from user
// Purpose is to examine use of <iomanip.h> and how setw is used
// Created by Gary Paduana
// email : gary3141@home.com
// Written on 4.15.01
# include <iostream.h>

# include <iomanip.h> // library that has the setw output manipulator
int main ()
{
char letter; // letter is the symbol or letter made into a giant triangle
int width; // width is how far to go into the center of screen
int base; // base is how many symbols are on bottom line
int a; // a is how many lines down the triangle is
int b = 1; // b is how many symbols are displayed on each line
int counter = 0; // counter is how many times the loop executed
cout<<"This program will make a triangle of the symbol entered."<<endl;
cout<<"It must be an odd number for the triangle to form properly."<<endl;
cout<<"If an even number is entered, it will be lowered to the previous odd."<<endl;
while(cin) // This allows the program to loop until the user closes the window
{
cout<<"Enter a symbol or character."<<endl;
cin>>letter;
cout<<"Enter the number of characters the base should have."<<endl;
cin>>base;
width = (base / 2) + 5 - counter; // This is how far into the center it should space until it
//starts outputting the symbol
// It must first be given a value before it enters the loop
a = 1; // a is how many lines down the triangle is, and
natuarally it starts on the first line
while(width > 5) // It will loop and continue to output the symbol until it
//reaches 5 spaces from the left margin...
// so that everything isn't jammed against the side
{
width = (base / 2) + 5 - counter; // This is how far into the center it should space until it
starts outputting the symbol
cout<<setw(width); // setw is an output manipulator in the <iomanip.h>
//library. this tell the compiler how many lines
// to move until it first sends a character to the screen.
//It is currently set to move the value of
// "width" spaces to the right before it outputs.
while(b > 0) // This while loop will continue to output the desired
//symbol to the current line until it is equal to 1
{
cout<<letter; // outputs the letter or symbol entered
b--; // b is decremented so only so many letters are
//outputted per line
}
cout<<endl; // an endl is used to jump to the next line to output the

//next part of the triangle
b = (a * 2) - 1; // the number of symbols per line is found using
//this equation
width--; // the width is decremented so that everything is
// spaced properly
b = b + 2; // b is given 2 more symbols because it is on the next line
//, and every line has 2 more than the previous
a++; // this is how many lines into the triangle it is
counter++; // the counter is used to ensure proper spacing done
// by the width variable
}
cout<<endl<<endl; // endl is used to add some space between each time
//the program is executed
b = 1; // b is returned to 1 because the program started over
counter = 0; // counter is returned to 0 because the program started
}
return 0;
}
*********************End of Example ************************************
CHAPTER 12

Microsoft Foundations Classes
The MFC library provides it own version of C's file processing. This is done through a class
named CStdioFile. The CStdioFile class is derived from CFile.
As done for the FILE structure, to start normal file input/outputoperations, declare a
variable of type CStdioFile. This class has five constructors whose syntaxes are:
CStdioFile();
CStdioFile(CAtlTransactionManager* pTM);
CStdioFile(FILE* pOpenStream);
CStdioFile(LPCTSTR lpszFileName, UINT nOpenFlags);
CStdioFile(LPCTSTR lpszFileName, UINT nOpenFlags, CAtlTransactionManager*
pTM);
The default constructor allows you to initiate file processing without giving much detail. If
you use it, you can then call the Open() method that the CStdioFile class inherits
fromCFile. Pass the same arguments you would for a CFile variable.
1. To create a new application, on the main menu, click File -> New Project...
2. In the middle list, click MFC Application
3. Set the Name to LoanPreparation1
4. Click OK
5. In the first page of the MFC Application Wizard, click Next
6. In the second page of the wizard, click Dialog Box
7. Click Next
8. In the third page of the wizard, change the Dialog Title to Loan Preparation
9. Click Next twice
10. Click Finish
11. On the dialog box, click TODO: and press Delete
12. Press the OK button and press Delete
13. Click the Cancel button to select it
14. In the Properties window, click Caption, type Close and press Enter
15. Design the dialog box as follows:

Control Caption ID
Right Align
Text
Static Text Prepared By:
Edit Control IDC_CUSTOMERNAME
Static Text Prepared For:
Edit Control IDC_EMPLOYEENAME
Static Text ________________
Static Text Loan Amount:
Edit Control IDC_PRINCIPAL True
Static Text Interest Rate:
Edit Control IDC_INTERESTRATE True
Static Text %
Static Text Paid In:
Edit Control IDC_PERIODS True
Static Text Months

Button Evaluate IDC_EVALUATE
Static Text _________________
Static Text Future Value:
Edit Control IDC_FUTUREVALUE True
Static Text Monthly Payment:
Edit Control IDC_MONTHLYPAYMENT True
Static Text _________________
Static Text Save As:
Edit Control IDC_FILESAVE True
Button Save IDC_SAVE_BTN
Static Text File to Open:
Edit Control IDC_FILEOPEN True
Button Open IDC_OPEN_BTN
Static Text File Name:
Button Reset IDC_RESET_BTN
Button Close IDCANCEL
16. Right-click each edit control, click Add Variable, select the category as Value, set the
options as follows and click Finish on each:
Control ID Category Variable Type Variable Name
IDC_CUSTOMERNAME Value CString m_CustomerName
IDC_EMPLOYEENAME Value CString m_EmployeeName
IDC_PRINCIPAL Value CString m_Principal
IDC_INTERESTRATE Value CString m_InterestRate
IDC_PERIODS Value CString m_Periods
IDC_FUTUREVALUE Value CString m_FutureValue
IDC_MONTHLYPAYMENT Value CString m_MonthlyPayment
IDC_FILESAVE Value CString m_FileSave
IDC_FILEOPEN Value CString m_FileOpen
17. Access the source file of the dialog box and change the initializations in the
constructor as follows:

1. CLoanPreparation1Dlg::CLoanPreparation1Dlg(CWnd* pParent /*=NULL*/)
2. : CDialogEx(CLoanPreparation1Dlg::IDD, pParent)
3. , m_CustomerName(_T(""))
4. , m_EmployeeName(_T(""))
5. , m_Principal(_T("0.00"))
6. , m_InterestRate(_T("0.00"))
7. , m_Periods(_T("0"))
8. , m_FutureValue(_T("0.00"))
9. , m_MonthlyPayment(_T("0.00"))
10. , m_FileSave(_T(""))
11. , m_FileOpen(_T(""))
12. {
13. m_hIcon = AfxGetApp()->LoadIcon(IDR_MAINFRAME);
}
14. Return to the dialog box
15. Double-click the Evaluate button
16. Implement the event as follows:
17. void CLoanPreparation1Dlg::OnBnClickedEvaluate()
18. {
19. UpdateData(TRUE);
20.
21. double Principal = _wtof(m_Principal);
22. double InterestRate = _wtof(m_InterestRate) / 100;
23. double Periods = _wtof(m_Periods) / 12;
24. double InterestAmount = Principal * InterestRate * Periods;
25. double FutureValue = Principal + InterestAmount;
26. double MonthlyPayment = FutureValue / _wtof(m_Periods);
27.
28. m_FutureValue.Format(L"%.2f", FutureValue);
29. m_MonthlyPayment.Format(L"%.2f", MonthlyPayment);
30.
31. UpdateData(FALSE);
}
32. Return to the dialog box
33. Double-click the Reset button
34. Implement the event as follows:
35. void CLoanPreparation1Dlg::OnBnClickedResetBtn()
36. {
37. m_CustomerName = L"";
38. m_EmployeeName = L"";
39. m_Principal = L"0.00";
40. m_InterestRate = L"0.00";
41. m_Periods = L"0.00";
42. m_FutureValue = L"0.00";
43. m_MonthlyPayment = L"0.00";
44. m_FileSave = L"";
45. m_FileOpen = L"";

46.
47. UpdateData(FALSE);
}
CHAPTER QUIZ
COURSE TOPIC : Introduction to Visual C++/ MFC Application

I. Objectives:
 To learn and understand how to use visual c++ objects
 To be able to apply Microsoft Foundation Classes
II. Tasks / Procedure / Instructions:
Make an MFC application that would ask the users to enter a pizza combo. Each
combination has a corresponding price (set your own prices). Additional fees will be
due for every extra toppings that the users may wish to add. The application must
also compute for the total amount payable by the user (customer).
See the sample output below.

A tutorial on C++ Programming

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