C++ AND CATEGORIES OF SOFTWARE

Using
C++
Programming Fundamentals
Lecturer 2

Today’s Lecture
 Software Categories
 System Software
 Application Software
 Introduction to ‘C’ Language
 History
 Evolution
 Justification
 Development Environment of ‘C’

There are two main categories of software
 System software
 Application Software

TWAIN
Technology Without An Interesting Name

ANSI C
American National standard Institute (ANSI)

Tools of the trade
 Editor
 Interpreter and Compilers
 Debuggers

Integrated Development Environment
(IDE)
It contains
 Editor
 Compilers
 Debugger
 Linkers
 Loaders

Preprocessor program
processes the code.
Loader puts program in
memory.
CPU takes each
instruction and executes it,
possibly storing new data
values as the program executes.
Compiler creates object code and
stores
it on disk.
Linker links the object
code with the libraries
Loader
Primary Memory
Compiler
Editor
Preprocessor
Linker
Primary Memory
.
.
.
.
.
.
.
.
.
.
.
.
Disk
Disk
Disk
CPU
Disk
Disk
Program is created in the editor and
stored on disk.

#include <iostream>
using namespace std;
void main ( )
{
cout << “ Welcome to UET TAXILA”;
}

The Parts of a C++ Program
// sample C++ program
#include <iostream>
int main()
{
cout << "Hello, there!";
return 0;
}
preprocessor directive
comment
which namespace to use
beginning of function named main
beginning of block for main
output statement
end of block for main
string literal
send 0 to operating system

Structure of a C++ program
Source code
1. // my first program in C++
2. # include <iostream>
3.
4. int main ()
5. {
6. std::cout<<“Hello Word!”;
7. }
Output
Hello Word!

Components of a C++ program
 Line 1: // my first program in C++
 Lines beginning with two slash signs (//) are
comments by the programmer and have no effect on
the behavior of the program.
 Programmers use them to include short
explanations or observations concerning the code or
program. In this case, it is a brief introductory
description of the program.

Comments
 Comments are for the reader, not the compiler
 Two types:
 Single line
// This is a C++ program. It prints the sentence:
// Welcome to C++ Programming.
 Multiple line
/*
You can include comments that can
occupy several lines.
*/

Single-Line Comments
Begin with // through to the end of line:
int length = 12; // length in inches
int width = 15; // width in inches
int area; // calculated area
// calculate rectangle area
area = length * width;

Multi-Line Comments
 Begin with /*, end with */
 Can span multiple lines:
/* this is a multi-line
comment
*/
 Can begin and end on the same line:
int area; /* calculated area */

Components of a C++ program (Cont.)
 Line 2: #include <iostream>
 Lines beginning with a hash sign (#) are directives
read and interpreted by what is known as the
preprocessor.
 In this case, the directive #include <iostream>,
instructs the preprocessor to include a section of
standard C++ code, known as header iostream, that
allows to perform standard input and output
operations.

The #include Directive
 Inserts the contents of another file into the program
 This is a preprocessor directive, not part of C++
language
 #include lines not seen by compiler
 Do not place a semicolon at end of #include line

Preprocessor Directives
 C++ has a small number of operations
 Many functions and symbols needed to run a C++
program are provided as collection of libraries
 Every library has a name and is referred to by a
header file
 Preprocessor directives are commands supplied to
the preprocessor
 All preprocessor commands begin with #

Preprocessor Directives (continued)
 Syntax to include a header file:
 For example:
#include <iostream>
 Causes the preprocessor to include the header file iostream
in the program

namespace and Using cin and cout in a
Program
 cin and cout are declared in the header file
iostream, but within std namespace
 To use cin and cout in a program, use the following
two statements:
#include <iostream>

 Line 3: A blank line.
 Blank lines have no effect on a program. They simply
improve readability.

 Line 4: int main ( )
 This line initiates the declaration of a function.
Essentially, a function is a group of code statements
which are given a name: in this case, this gives the
name "main" to the group of code statements that
follow.
 The execution of all C++ programs begins with
the main function regardless of where the function is
actually located within the code.

Whitespaces
 Every C++ program contains whitespaces
 Include blanks, tabs, and newline characters
 Used to separate special symbols, reserved words,
and identifiers
 Proper utilization of whitespaces is important
 Can be used to make the program readable

 Line 6: std::cout << "Hello World!";
 This statement has three parts: First, std::cout,
which identifies the standard character output
device (usually, this is the computer screen).
 Second, the insertion operator (<<), which
indicates that what follows is inserted into std::cout.
 Finally, a sentence within quotes ("Hello world!"), is
the content inserted into the standard output.

 Stream manipulator std::endl
 Outputs a newline.
 Flushes the output buffer.
 The notation std::cout specifies that we are using a
name (cout ) that belongs to a “namespace” (std).

The Basics of a C++ Program
 Function: collection of statements; when executed,
accomplishes something
 May be predefined or standard
 Syntax: rules that specify which statements
(instructions) are legal
 Programming language: a set of rules, symbols, and
special words
 Semantic rule: meaning of the instruction

The cout Object
 Displays output on the computer screen
 You use the stream insertion operator << to send
output to cout:
cout << "Programming is fun!";

The cout Object
 Can be used to send more than one item to cout:
cout << "Hello " << "there!";
Or:
cout << "Hello ";
cout << "there!";

The cout Object
 This produces one line of output:
cout << "Programming is ";
cout << "fun!";

cout << “Hello…”
VariableInsertion
operator
Object
Hello…
Output in C++

The endl Manipulator
 You can use the endl manipulator to start a new line
of output. This will produce two lines of output:
cout << "Programming is" << endl;
cout << "fun!";

Manipulator
 Manipulators are the operators in C++ for
formatting the output.
 The data is manipulated according to the desired
output.

cout << "Programming is" << endl;
cout << "fun!";
Programming is
fun!

 You do NOT put quotation marks around endl
 The last character in endl is a lowercase L, not the
number 1.
endl This is a lowercase L

Escape Sequence
 The backslash is called the escape character.
 An escape sequence is a series of characters that represents a special character
 An escape sequence begins with a backslash character (), which indicates that
the character(s) that follow should be treated in a special way.
 It tells the compiler that the next character is “escaping”.
 Escape Sequence are special character used in control string to modify the
format of output.

The n Escape Sequence
 You can also use the n escape sequence to start a
new line of output. This will produce two lines of
output:
cout << "Programming isn";
cout << "fun!";
Notice that the n is INSIDE
the string.

The n Escape Sequence
cout << "Programming isn";
cout << "fun!";
Programming is
fun!

Keywords / Reserve Words:
 The predefined words of the C++ that are used for
special purposes in the source program.
 Also known as reserved words
 Always written in lowercase
 There are 63 keywords in c++.
Tokens:
 In C++, a source program consists of keywords,
variables (or identifiers), constants, operators,
punctuators.
 These elements of a c++ program are called tokens.

C++ Key Words
You cannot use any of the C++ key words as an
identifier. These words have reserved meaning.

Identifier:
 The unique names used in the program to represent
the variables, constants, functions, and labels etc. are
called identifiers.
 The name of identifier may be 31 characters long. If
the name is more than 31 characters long , then first
31 characters will be used by the compiler.
An identifier Rules
 consist of alphabets, digits, and underscore.
 The first character of identifier name must be an alphabetic
letter or underscore.
 The keywords cannot be used as identifier name.

Types of identifiers:
 Standard Identifier
 There are also predefined identifiers in c++
 The predefined identifiers that are used for special
purposes in the source program are called the standard
identifiers.
 E.g cin, cout
 User-defined identifier
 the identifiers defined by the user in the program are
called user-defined identifers.
 E.g variables, user-defined functions, labels

Valid and Invalid Identifiers
IDENTIFIER VALID? REASON IF INVALID
totalSales Yes
total_Sales Yes
total.Sales No Cannot contain .
4thQtrSales No Cannot begin with digit
totalSale$ No Cannot contain $

Variable
 Pic of the memory
 25
 10323
name
of the
variable

Variable
Variable starts with
1. Character
2. Underscore _ (Not Recommended)

Variable Names
 A variable name should represent the purpose of the
variable. For example:
itemsOrdered
The purpose of this variable is to hold the number of
items ordered.

Variable
Variable is the name of a location in
the memory
e.g. x= 2;

Variable Definition in Program
Variable Definition

Variable
In a program a variable has:
1. Name
2. Type
3. Size
4. Value

Assignment Operator
=
x = 2
X
2

Assignment Operator
L.H.S = R.H.S.
X+ 3 = y + 4 Wrong
Z = x +4
x +4 = Z Wrong

Data type
 int i ; ->
Declaration line
i

#include <iostream>
int main ( )
{
int x ;
int y ;
int z ;
x = 10 ;
y = 20 ;
z = x + y ;
cout << " x = " ;
cout << x ;
cout << " y = " ;
cout << y ;
cout << " z =x + y = " ;
cout << z ;
return 0;
}

int x, y, z ;
int x; int y; int z ;

The cin Object
 Standard input object
 Like cout, requires iostream file
 Used to read input from keyboard
 Information retrieved from cin with >>
 Input is stored in one or more variables

Input in C++
>> 45
Object
Extraction
Operator
myVariable

cin

The cin Object
 cin converts data to the type that matches the
variable:
int height;
cout << "How tall is the room? ";
cin >> height;

Displaying a Prompt
 A prompt is a message that instructs the user to
enter data.
 You should always use cout to display a prompt
before each cin statement.
cout << "How tall is the room? ";
cin >> height;

The cin Object
 Can be used to input more than one value:
cin >> height >> width;
 Multiple values from keyboard must be separated
by spaces
 Order is important: first value entered goes to first
variable, etc.

The cin Object Gathers Multiple Values in Program

The cin Object Reads Different
Data Types in Program

C++ Data Types
C++ DataTypes
DerivedTypes
Array
Function
Pointer
Reference
Userdefined
Types
Structure
Union
Class
Enumeration
Built InTypes
EmptyType Floating TypesIntegral Types
Int char float doublevoid

C++ Primitive Data Types
Primitive types
integral floating
char short int long bool float double long double
unsigned

Data Types
1. int
2. short
3. long
4. float
5. double
6. char

C++ Data Type
A type defines a set of values and a
set of operations that can be applied on
those values. The set of values for each
type is known as the domain for the type.
C++ contains 5 standard types:
void int char float bool
Standard
Data Types

void
The void type has no values and no
operations. In other words, both the set
of values and the set of operations are
empty. Although this might seem unusual,
we will see later that it is a very
useful data type.

Integer
An integer type is a number without a
fractional part. It is also known as an
integral number. C++ supports three different
sizes of the integer data type: short int, int
and long int.
sizeof(short int)<= sizeof(int)<= sizeof(long int)
Short int
int
long int

Integer Data Types
• Integer variables can hold whole numbers such
as 12, 7, and -99.

Defining Variables
 Variables of the same type can be defined
- On separate lines:
int length;
int width;
unsigned int area;
- On the same line:
int length, width;
unsigned int area;
 Variables of different types must be in different definitions

Integer Types in Program
This program has three variables: checking,
miles, and days

Literals
 Literal: a value that is written into a program’s code.
"hello, there" (string literal)
12 (integer literal)

Integer Literal in Program
20 is an integer literal

Integer Literals
 An integer literal is an integer value that is typed into
a program’s code. For example:
itemsOrdered = 15;
In this code, 15 is an integer literal.

Integer Literals in Program
Integer Literals

Integer Literals
 Integer literals are stored in memory as int by
default
 To store an integer constant in a long memory
location, put ‘L’ at the end of the number: 1234L
 Constants that begin with ‘0’ (zero) are base 8: 075
 Constants that begin with ‘0x’ are base 16: 0x75A

The char Data Type
 Used to hold characters or very small integer values
 Usually 1 byte of memory
 Numeric value of character from the character set is
stored in memory:
CODE:
char letter;
letter = 'C';
MEMORY:
letter
67

The ‘char’ data type:
 Used to store a single character such as ‘a’, ‘$’ etc.
 When the character is stored into a variable, the
ASCII value is stored into the variable.
 The ASCII value of ‘A’ is 65 and ‘a’ is 97.
 By default the character data type is unsigned
because the ASCII values are positive.
 The range for unsigned ‘char’ data type is from 0 to
255.
 For signed ‘char’ its -128 to 127
 ASCII stands for American Standard Code for
Information Interchange

char Data Type
 The smallest integral data type
 Used for characters: letters, digits, and special
symbols
 Each character is enclosed in single quotes
 'A', 'a', '0', '*', '+', '$', '&'
 A blank space is a character and is written ' ',
with a space left between the single quotes

Character Literals
 Character literals must be enclosed in single quote
marks. Example:
'A'

Character Strings
 A series of characters in consecutive memory
locations:
"Hello"
 Stored with the null terminator, 0, at the end:
 Comprised of the characters between the " "
H e l l o 0

string Type
 Programmer-defined type supplied in
ANSI/ISO Standard C++ library
 Sequence of zero or more characters
 Enclosed in double quotation marks
 Null: a string with no characters
 Each character has relative position in string
 Position of first character is 0 (zero)
 Length of a string is number of characters in it
 Example: length of "William Jacob" is 13

The C++ string Class
 Special data type supports working with strings
 #include <string>
 Can define string variables in programs:
string firstName, lastName;
 Can receive values with assignment operator:
firstName = “Kristen";
lastName = “Stewart";
 Can be displayed via cout
cout << firstName << " " << lastName;

String Literals in Program
These are string literals

Floating Point
A floating-point type is a number with a
fractional part, such as 43.32. The C++
language supports three different sizes of
floating-point: float, double and long double.
sizeof(float)<= sizeof(double)<= sizeof(long double)
float
double
long double

Floating-Point Data Types
 The floating-point data types are:
float
double
long double
 They can hold real numbers such as:
12.45 -3.8
 Stored in a form similar to scientific notation
 All floating-point numbers are signed

Floating-Point Data Types (continued)
 Maximum number of significant digits (decimal
places) for float values is 7
 Maximum number of significant digits for double is
15
 Precision: maximum number of significant digits
 Float values are called single precision
 Double values are called double precision

Floating-Point Literals
 Can be represented in
 Fixed point (decimal) notation:
31.4159 0.0000625
 E notation:
3.14159E1 6.25E-5
 Are double by default
 Can be forced to be float (3.14159f) or long double
(0.0000625L)

Floating-Point Data Types in Program

The bool Data Type
 Represents values that are true or false
 bool variables are stored as small integers
 false is represented by 0, true by 1:
bool allDone = true;
bool finished = false;
allDone finished
1 0

Determining the Size of a Data Type
The sizeof operator gives the size of any data type
or variable:
double amount;
cout << "A double is stored in "
<< sizeof(double) << "bytesn";
cout << "Variable amount is stored in
"
<< sizeof(amount)
<< "bytesn";

Overflow and Underflow:
 An overflow occurs when the value assigned to a
variable is more than the maximum allowable
limit.
 An underflow occurs when the value assigned to
a variable is less then the minimum allowable
limit.

Variable Assignments and Initialization
 An assignment statement uses the = operator to
store a value in a variable.
item = 12;
 This statement assigns the value 12 to the item
variable.

Assignment
 The variable receiving the value must appear on the
left side of the = operator.
 This will NOT work:
// ERROR!
12 = item;

Variable Initialization
 To initialize a variable means to assign it a value
when it is defined:
int length = 12;
 Can initialize some or all variables:
int length = 12, width = 5, area;

Variable Initialization in Program

Scope
 The scope of a variable: the part of the program in
which the variable can be accessed
 A variable cannot be used before it is defined

Variable Out of Scope in Program

Local Variables
 Variables that are declared inside a function or block
are local variables. They can be used only by
statements that are inside that function or block of
code.
 Local variables are not known to functions outside
their own.

Local Variables
#include <iostream>
int main ()
{
// Local variable declaration:
int a, b; int c;
// actual initialization
a = 10;
b = 20;
c = a + b;
cout << c;
return 0;
}

Global Variables
 Global variables are defined outside of all the
functions, usually on top of the program. The global
variables will hold their value throughout the life-
time of your program.
 A global variable can be accessed by any function.
That is, a global variable is available for use
throughout your entire program after its declaration.

Global Variables
#include <iostream>
// Global variable declaration:
int g;
int main ()
{
int a, b;
// actual initialization
a = 10;
b = 20;
g = a + b;
cout << g;
return 0;
}

A program can have same name for local and global variables but
value of local variable inside a function will take preference. For example:
#include <iostream>
// Global variable declaration:
int g = 20;
int main ()
{
int g = 10;
cout << g;
return 0;
} // Output of Program g = 10

Initializing Local and Global Variables
 When a local variable is defined, it is not initialized
by the system, you must initialize it yourself. Global
variables are initialized automatically by the system
when you define them as follows
Data Type Initializer
int 0
char '0'
float 0.0
double 0.0
pointer NULL

Arithmetic Operators
 Used for performing numeric calculations
 C++ has unary, binary, and ternary operators:
 unary (1 operand) -5
 binary (2 operands) 13 - 7
 ternary (3 operands) exp1 ? exp2 : exp3

Arithmetic operators
Plus +
Minus -
Multiply *
Divide /
Modulus %

Arithmetic operators
i + j
x * y
a / b
a % b

Binary Arithmetic Operators
SYMBOL OPERATION EXAMPLE VALUE OF
Ans
+ addition ans = 7 + 3; 10
- subtraction ans = 7 - 3; 4
* multiplication ans = 7 * 3; 21
/ division ans = 7 / 3; 2
% modulus ans = 7 % 3; 1

#include <iostream>
void main ( )
{
int age1, age2, age3, age4, age5, age6, age7, age8, age9, age10 ;
int TotalAge ;
int AverageAge ;
cout << “ Please enter the age of student 1: “ ;
cin >> age1 ;
cout << “ Please enter the age of student 2: “ ;
cin >> age2 ;
:
:
TotalAge = age1+ age2 + age3+ age4+ age5+age6+ age7+ age8+age9 + age10 ;
AverageAge = TotalAge / 10 ;
cout<< “The average age of the class is :” << AverageAge ;
}

Quadratic Equation
 In algebra
y = ax2 + bx + c
 In C
y = a*x*x + b*x + c

Discriminant
b2 - 2a
= b*b - 4*a*c /2 *a Incorrect answer
Solution
= (b*b - 4*a*c) /(2 *a) Correct answer
4c

 No expression on the left hand side
of the assignment
 Integer division truncates
fractional part
 Liberal use of
brackets/parenthesis

A Closer Look at the / Operator
 / (division) operator performs integer division if
both operands are integers
cout << 13 / 5; // displays 2
cout << 91 / 7; // displays 13
 If either operand is floating point, the result is
floating point
cout << 13 / 5.0; // displays 2.6
cout << 91.0 / 7; // displays 13.0

A Closer Look at the % Operator
 % (modulus) operator computes the remainder
resulting from integer division
cout << 13 % 5; // displays 3
 % requires integers for both operands
cout << 13 % 5.0; // error

% = Remainder
5 % 2 = 1
2 % 2 = 0

Precedence
 Highest: ( )
 Next: * , / , %
 Lowest: + , -

operator=
Compound Assignment Operators

 counter += 3 ;
same as
 counter = counter + 3 ;
+=

 counter -= 5 ;
same as
 counter = counter – 5 ;
-=

 x %= 2 ;
Same As
 x = x % 2 ;
%=

Precedence
Operators Associativity
(), ++postfix, -- postfix Left to right
++ prefix, ++prefix Left to right
*,/,% Left to right
+,- Left to right
=,+=,-=,*=,/= Right to left

Expressions
 If all operands are integers
 Expression is called an integral expression
 Yields an integral result
 Example: 2 + 3 * 5
 If all operands are floating-point
 Expression is called a floating-point expression
 Yields a floating-point result
 Example: 12.8 * 17.5 - 34.50

Mixed Expressions
 Mixed expression:
 Has operands of different data types
 Contains integers and floating-point
 Examples of mixed expressions:
2 + 3.5
6 / 4 + 3.9
5.4 * 2 – 13.6 + 18 / 2

Mixed Expressions (continued)
 Evaluation rules:
 If operator has same types of operands
 Evaluated according to the type of the operands
 If operator has both types of operands
 Integer is changed to floating-point
 Operator is evaluated
 Result is floating-point
 Entire expression is evaluated according to precedence rules

Rules for Division
 C++ treats integers differently from decimal
numbers.
 100 is an int type.
 100.0 , 100.0000, and 100. are double type.
 The general rule for division of int and double
types is:
 double/double -> double (normal)
 double/int -> double (normal)
 int/double -> double (normal)
 int/int -> int (note: the decimal part is discarded)

Rules for Division
 Examples:
 220. / 100.0 double/double -> double result is 2.2
 220. / 100 double/int -> double result is 2.2
 220 / 100.0 int/double -> double result is 2.2
 220 / 100 int/int -> int result is 2
 Summary: division is normal unless both the
numerator and denominator are int, then the result is
an int (the decimal part is discarded).

Assignment Conversions
 A decimal number assigned to an int type variable is
truncated.
 An integer assigned to a double type variable is
converted to a decimal number.
 Example 1:
double yy = 2.7;
int i = 15;
int j = 10;
i = yy; // i is now 2
yy = j; // yy is now 10.0

 Example 2:
int m, n;
double xx;
m = 7;
n = 2.5;
xx = m / n;
n = xx + m / 2;
// What is the value of n?

 Example 2:
int m, n;
double xx;
m = 7;
n = 2.5; // 2.5 converted to 2 and assigned to n
xx = m/n; // 7/2=3 converted to 3.0 and assigned to xx
n = xx+m/2;
// m/2=3 : integer division
// xx+m/2 : double addition because xx is double
// convert result of m/2 to double (i.e. 3.0)
// xx+m/2=6.0
// convert result of xx+m/2 to int (i.e. 6)
// because n is int

Forcing a Type Change
 You can change the type of an expression with a cast
operation.
 Syntax:
variable1 = type(variable2);
variable1 = type(expression);
 Example:
int x=1, y=2;
double result1 = x/y; // result1 is 0.0
double result2 = double(x)/y; // result2 is 0.5
double result3 = x/double(y); // result3 is 0.5
double result4 = double(x)/double(y);// result4 is 0.5
double result5 = double(x/y); // result5 is 0.0
int cents = int(result4*100); // cents is 50

When You Mix Apples with Oranges: Type
Conversion
 Operations are performed between operands of the
same type.
 If not of the same type, C++ will convert one to be
the type of the other
 This can impact the results of calculations.

Hierarchy of Types
Highest:
Lowest:
Ranked by largest number they can hold
long double
double
float
unsigned long
long
unsigned int
int

Type Coercion
 Type Coercion: automatic conversion of an operand
to another data type
 Promotion: convert to a higher type
 Demotion: convert to a lower type

Coercion Rules
1) char, short, unsigned short automatically
promoted to int
2) When operating on values of different data types,
the lower one is promoted to the type of the higher
one.
3) When using the = operator, the type of expression
on right will be converted to type of variable on left

Type Casting
 Used for manual data type conversion
 Useful for floating point division using int:
double m;
m = static_cast<double>(y2-y1)
/(x2-x1);
 Useful to see int value of a char variable:
char ch = 'C';
cout << ch << " is "
<< static_cast<int>(ch);

C-Style and Prestandard Type Cast Expressions
 C-Style cast: data type name in ()
cout << ch << " is " << (int)ch;
 Prestandard C++ cast: value in ()
cout << ch << " is " << int(ch);
 Both are still supported in C++, although
static_cast is preferred

Interesting Problem
Given a four-digit integer,
separate and print the digits on
the screen

Analysis
 Number = 1234
 Take the remainder of the above number after dividing by 10
Eg 1234 / 10 gives remainder 4
1234 % 10 = 4
 Remove last digit
 1234/10 = 123.4
 123 (Truncation due to Integer Division)
 123 %10 gives 3
 123/10 = 12.3
 12 % 10 gives remainder 2
 12/10 = 1.2
 Final digit remains

Code
#include <iostream>
void main ( )
{
int number;
int digit;
cout << “Please enter a 4 digit integer : ”;
cin >> number; 1234
digit = number %10; 4
cout <<“The digit is: “ << digit << ‘n’; // first digit; and then << ‘n’
number = number / 10; 123
digit = number % 10; 3
cout <<“The digit is: “ << digit << ‘n’;
digit = number % 10 ; 2
cout <<“The digit is: “ << digit << ‘n’;
digit = number % 10;
cout <<“The digit is: “ << digit;
}

Named Constants
 Named constant (constant variable): variable whose
content cannot be changed during program
execution
 Used for representing constant values with
descriptive names:
const double TAX_RATE = 0.0675;
const int NUM_STATES = 50;
 Often named in uppercase letters
 Use #define preprocessor directive instead of const
definitions

Difference between #define and const
‘#define’ directive ‘const’ Qualifier
Used as preprocessor directive Used as a statement
Not terminated with the ; Terminated with the ;
Data type of constant identifier
is not specified
Data type is specified

Postfix expressions
Two postfix operators: ++ (postfix increment)
-- (postfix decrement)
the effect of a++ is the same as a = a + 1
the effect of a-- is the same as a = a - 1

Prefix expressions
Two prefix operators: ++ (prefix increment)
-- (prefix decrement)
the effect of ++a is the same as a = a + 1
the effect of --a is the same as a = a - 1

163
Relational Operators and the Type char
 '0' through '9' have ASCII code values 48 through 57
'0' < '1' < . . . < '9'
 'A' through 'Z' have ASCII code values 65 through 90
'A' < 'B' < . . .< 'Z'
 'a' through 'z' have ASCII code values 97 through 122
'a' < 'b' < . . .< 'z'

C++ Standard
Library Header Files

Programming Style
 The visual organization of the source code
 Includes the use of spaces, tabs, and blank lines
 Does not affect the syntax of the program
 Affects the readability of the source code

Programming Style
Common elements to improve readability:
 Braces { } aligned vertically
 Indentation of statements within a set of braces
 Blank lines between declaration and other
statements
 Long statements wrapped over multiple lines with
aligned operators

C++ AND CATEGORIES OF SOFTWARE

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