PPS_unit_2_gtu_sem_2_year_2023_GTUU.pptx

Subject Overview
Sr. no. Units % Weightage
1 Introduction to computer and programming 11 %
2 Fundamentals of C 9 %
3 Control structure in C 11 %
4 Array & String 13 %
5 Functions 11 %
6 Recursion 9 %
7 Pointers 9 %
8 Structure 9 %
9 Dynamic memory allocation 9 %
10 File management 9 %
Reference books:
1. Programming in ANSI C by Balagurusamy
2. C Programming: Test Your Skills, 1/e by Ashok Kamthane
3. Programming With Ansi And Turbo C book : Ashok Kamthane ...
4. Programming in C Ansi standard, by Yashwant Kanetkar

 Topics to be covered
 Introduction
 Features of ‘C’
 Structure of C Program
 Comments
 Header files
 Data types in C
 Constants in C
 Variable
 Keywords

INTRODUCTION
 The C programming language was
designed by Dennis Ritchie at Bell
Laboratories in the early 1970s
 C is a general-purpose programming
language that is extremely popular,
simple and flexible. It is machine-
independent, structured programming
language which is used extensively in
various applications.

 Features of ‘C’
1) Simple:
 C uses English language to write the code. Also the syntax used in C coding are simple
which can be easily understood by programmer.
2) Structured programming language:
 C is a structured programming language in the sense that we can break the program into
parts using functions
3) Middle level Language:
 C combines the features of both high-level language and middle level language. C is near to
machine as well as human understandable language and also uses English language while
coding.
4) Platform dependent:
 C language is said to be platform dependent whenever the program is execute in the same
operating system where that was developed and compiled but not run and execute on other
operating system. C is platform dependent programming language.

 Features of ‘C’
5) Portability:
 It is the concept of carrying the instruction from one system to another system. When we
write and compile any C program on window operating system that program easily run on
other window based system.
6) Powerful:
 C is a very powerful programming language, it have a wide verity of data types, functions,
control statements, decision making statements, etc.
7) Case Sensitive:
 Case Sensitive is another features of C Language. It is a case sensitive programming
language. In C programming ‘int and INT' both are different. It is also main feature of C
Language.
8) Compiler Based:
 C is a compiler based programming language that means without compilation no C program
can be executed. First we need compiler to compile our program and then execute.

 Comments
 Comments are used in program to improve readability and understanding
 Comments are not executed.
 It generally help the programmer to understand the various operations.
 C supports two types of comments:
1. Single line comment: Single line comment starts with the double forward slash //
and it will continue up till the end of the line.
 For example: // this code is for addition
2. Multiline comment: Multiline comment starts with /* and ends with */
 For example: /* program name: addition
date: 12-12-2020
author: Dennis Ritchie */

 Header files
 Header files contain set of predefined library functions that we can include in our
program.
 In C libraries are available for various inbuilt functions.
 Example:
#include<stdio.h>
 stdio means for Standard input output functions.
 printf()
Syntax: printf(“Control string”);
 scanf()
Syntax: scanf(“control string”,&variable name);

 Header files
 #include<math.h>
 This header file is used for mathematical functions like, sqrt(), pow ( ), sin ( ) ,etc….
 #include
 It is a preprocessor directives. The #include directive tells the C preprocessor to include
the contents of the file specified in the input stream to the compiler and then continue
with the rest of the original file.

 Data types in C
 A data type is a classification of various types of data, as floating-point, integer, or string.
C is rich in its data types to allow programmer to select appropriate type of data type.
 The type of a variable determines how much space it occupies in storage.
Data types in C
Primary Data type
(int, char, float, double)
Secondary Data type
Derived data type
(array, pointer, etc..)
User defined data types
(structure, union, enum)
Fig: Data types in C

1. Primary data types
 Primary data types are built in data types. They are directly supported by machine. They
are also known as fundamental data types.
1) int
 int is integer which is whole number without fraction part. Its range is machine
dependent values. C has 3 classes of integer storage namely short int, int and long int.
All of these data types have signed and unsigned forms.
signed unsigned
Format
specifier
size
(bit)
size
(byte)
Range
Format
specifier
size
(bit)
size
(byte)
Range
short int %hd 8 1 -128 to 127 %hu 8 1 0 to 255
int %d 16 2 -32768 to 32767 %u 16 2 0 to 65535
long int
%ld 32 4 -2,14,74,83,648 to
2,14,74,83,647
%lu 32 4 0 to 4,29,49,67,295

2) char
 char data type can store single character of alphabet or digit or special symbol. Each
character is assigned some integer value which is known as ASCII values.
3) float
 float data type can store floating point number which represents a real number with decimal
point and fractional part. When the accuracy of the floating point number is insufficient, we
can use the double to define the number. The double is same as float but with longer
precision. To extend the precision further we can use long double which consumes 80 bits of
memory space.
signed unsigned
Format
specifier
size
(bit)
size
(byte)
Range
Format
specifier
size
(bit)
size
(byte)
Range
char %c 8 1 -128 to 127 %c 8 1 0 to 255
Format
specifier
size
(bit)
size
(byte)
Range
float %f 32 4 1.2 e-38 to 3.4 e+38
double %lf 64 8 1.7e-308 to 1.7e+308
long float %Lf 80 10 3.4E-4932 to 1.1E+4932

2. Secondary data types
 Secondary data types are not directly supported by the machine. It is combination of
primary data types to handle real life data in more convenient way. It can be further
divided in two categories:
a) Derived data type
 Derived data type is extension of primary data type. It is built-in system and its
structure cannot be changed. Examples: Array, Pointer, etc…
b) User defined data types
 User defined data type can be created by programmer using combination of primary
data type and/or derived data type. Use can design it as per special requirements.
Examples: Structure, Union, enum, etc…

 Constants in C
 Constants are the terms that can't be changed during the execution of a program. For
example: 1, 2.5, "Programming is easy." etc. or Constant is something whose value does
not change throughout the program.
 In C, constants can be classified as:
Constants
Numeric constant Nonnumeric constant
Single character
constant
String constant
Fig: Types of Constant
Integer constant real constant

 Constants in C
1) integer constants:
 Integer constant is a number without decimal point and fractional part
 There are three types of integers constant:
i. Decimal integer:
Decimal integer consist of a set of digits, 0 to 9 having optional – or + sign. No other
characters are allowed like space, commas, and non-digit characters.
Ex: 123, -321, 0, +78
ii. Octal integer:
Octal integer consists of any combination of digits from the set 0 to 7. Octal numbers are
always preceded by 0.
Ex: 037, 0, 0551
iii. Hexadecimal integer:
Hexadecimal integer consists of any combination of digits from the set 0 to 9 and A to F
alphabets. It always starts with 0x or 0X. A represents 10, B represents 11… F represents
15. Ex: 0X2A, 0x95, 0xA47C.

Octal example:
int a =012;
printf(“given octal number : %o”,a);
printf( “given octal number in decimal: %d”,a);
Output:
given octal number : 12
given octal number in decimal: 10

 Constants in C
2) real constant:
 The number containing the fractional part is called real number. Ex: 0.0083, -0.75, +247.0, -
0.75.
 A real number may also be expressed in exponential notation.
 The general form is: mantissa e exponent, ex: 215.65 can be written as 2.1565e2.
 In exponential form, e2 means multiply by 102.
3) Single character constant:
 It contains single character enclosed within a pair of single quote mark.
 Ex: ‘5’, ‘A’, ‘;’, ‘ ‘
4) String constant:
 A string constant is a sequence of characters enclosed within a double inverted comma.
 The characters may be le ter, number, special character, blank space, etc…
 Ex: “DIET”, “1988”, “?A.B,!”, “5+3”, etc…
 ‘A’ is character but “A” is string.

 Variable
 Variables are memory location in computer's memory to store data. To indicate the
memory location, each variable should be given a unique name called identifier.
Identifiers are used for naming variables, functions and arrays.
 Variable names are just the symbolic representation of a memory location.
 Examples of variable name: sum, car_no, count etc.
int num;
float a,b;
char a;
 Rules to define variable name:
1. An identifier can be composed of letters (both uppercase and lowercase letters),
digits and underscore '_' only.
2. The first letter of identifier should be either a letter or an underscore.
3. They must not begin with a digit.
4. They can be of any of length however the first 8 characters are treated as significant
by the C compiler.
5. Reserved keywords can not be used as a variable.

 Keywords
 Keywords are the reserved words used in programming. Each keywords has fixed
meaning and that cannot be changed by user. For example:

OPERATORS
 An operator is a symbol that tells the compiler to perform certain mathematical
or logical operation. C has rich set of operators as below:
1. Arithmetic Operators
2. Relational Operators
3. Logical Operators
4. Assignment Operators
5. Increment and Decrement Operators
6. Conditional Operator
7. Bitwise Operators
8. Special Operators

1. Arithmetic Operators
 Arithmetic operators are used for mathematical calculation. C supports
following arithmetic operators
Sr.no Operator Meaning Explaination
1 +
Addition or unary
plus
a+ b (addition), +7 (unary plus)
2 -
Subtraction or
unary minus
a – b (subtraction), -8 (unary
minus)
3 * Multiplication a * b
4 / Division a / b
5 % Modulo division
a % b (this operator can be used
with only integer data type)

2. Relational Operators
 Relational operators are used to compare two numbers and taking decisions based
on their relation.
 Relational expressions are used in decision statements such as if, for, while, etc…
Sr.no Operator Meaning
1 < less than
2 <= less than or equal to
3 > greater than
4 >= greater than or equal to
5 == is equal to
6 != is not equal to

3. Logical Operators
 Logical operators are used to test more than one condition and make decisions
1 && logical AND (Both non zero then true, either is zero then false)
2 || logical OR (Both zero then false, either is non zero then true)
3 ! logical NOT (non zero then false, zero then true)
a b a&&b a||b
0 0 0 0
0 1 0 1
1 0 0 1
1 1 1 1

4. Assignment Operators
 Assignment operators are used to assign the result of an expression to a variable.
C also supports shorthand assignment operators which simplify operation with
assignment
1 = Assigns value of right side to left side
2 += a += 1 is same as a = a + 1
3 -= a -= 1 is same as a = a - 1
4 *= a *= 1 is same as a = a * 1
5 /= a /= 1 is same as a = a / 1
6 %= a %= 1 is same as a = a % 1

5. Increment and Decrement Operators
 These are special operators in C which are generally not found in other languages.
1 ++
 Increments value by 1.
 a++ is postfix, the expression is evaluated first
and then the value is incremented.
2 --
 Decrements value by 1.
 a-- is postfix, the expression is evaluated first
and then the value is decremented.

Write output of the following code.
#include<stdio.h>
#include<conio.h>
void main()
{
int x=4,y=5;
x = ++x * ++y;
y = y++ * x++;
printf(“ x = %d n y = %d”,x,y);
getch();
}

Write output of the following code.
#include<stdio.h>
#include<conio.h>
void main()
{
int x=4,y=5;
printf(“value of x = %d”, x++);
printf(“nvalue of x = %d”, x);
printf(“n value of ++y = %d”, ++y);
printf(“value of y++ = %d”, y);
getch()
}
OUTPUT:
value of x =4
value of x =5
value of ++y =6
value of y++ =6

6. Conditional Operator
 Ternary operator is known as Conditional Operator.
 A ternary operator pair “ ? :” is available in c to construct conditional expressions of
the form:
exp1?exp2:exp3
 Where exp1, exp2,exp3 are expression.
 The operator ?:works as follows: exp1 is evaluated first. if it is true, then the
expression exp2 evaluated and becomes the value of the expression. If exp1 is false ,
exp3 is evaluated and its value becomes the value of the expression.
a = 10;
b = 15;
X = (a>b) ? a : b;

7. Bitwise Operators
 Bitwise operators are used to perform operation bit by bit. Bitwise operators may
not be applied to float or double.
1 & bitwise AND
2 | bitwise OR
3 ^ bitwise exclusive OR
4 <<
shift left ( shift left means multiply
by 2)
5 >>
shift right ( shift right means
divide by 2)

8. Special Operators
 C supports some special operators of interest such as comma operator , sizeof
operator, pointer operator (& and *) (discuss in unit 6 pointer) and member
selection operators (. and - >).
1 & Address operator, it is used to determine address of the variable.
2 *
Pointer operator, it is used to declare pointer variable and to get
value from it.
3 ,
Comma operator. It is used to link the related expressions
together.
4 sizeof It returns the number of bytes the operand occupies.
5 . member selection operator, used in structure.
6 - > member selection operator, used in pointer to structure.

Arithmetic expression
 An arithmetic expression is a combination of variables ,
constants and operators arranged as per the syntax of the
language. We have used a number of simple expressions in the
examples discussed so far.
 C can handle any complex mathematical expressions. Some of
the examples e.g. C expressions are shown in next slide.
Remember that C does not have an operator for exponentiation.

Expressions
Algebraic Expression C Expression
ab-c a*b-c
(m+n)(x+y) (m+n)*(x+y)
(ab/c) (a*b)/c
x/y + c (x/y)+c
ab-c a*b-c

EVALUATION OF expressions
Expressions are evaluated using an assignment statement of the form:
Variable=Expression
Variable is any valid C variable name. When the statement is encountered, the
expression is evaluated first and the result then replaces the previous value of the
variable on the left-hand side. All variables used in the expression must be
assigned values before evaluation is attempted.
Example of evaluation statement are:
X= a*b-c;
Y=b/c*a;
Z=a-b/c+d;
When these statement are used in a program, the variables a,b,c and d must be
defined before they are used in the expressions.

Type Conversion or Type Casting
 When an operator has operands of different types, they are converted to a
common type, this is known as type casting or type conversion.
 Typecasting is making a variable of one data type to act like another data
type such as an int to float.
 There are two types of type casting:
1. Implicit Type Casting.
2. Explicit Type Casting.

Implicit Type Casting
 When complier automatically convert data type of the data then it is called
as a implicit type conversion.
Explicit Type Casting
 When type casting forcefully converts the value of one type into another
type then it is called as a explicit type conversion.
Syntax : (type)expression;

Example:
#include<stdio.h>
#include<conio.h>
void main()
{
int sum=47, n=10;
float avg;
avg=sum / n;
printf(“Result of Implicit Type Casting:
%f”, avg);
avg=(float)sum / (float)n;
printf(“Result of Explicit Type Casting: %f”,
avg);
// implicit type casting will print 4.0000
// explicit type casting will print 4.7000

 PROGRAM TO ILLUSTRATE TYPE CASTING
#include<stdio.h>
#include<conio.h>
Void main()
{
float num = 8.45;
printf(“Value of num = %fn”,num);
printf(“Value of num on Type casting = %dn,(int)num”);
getch();
}

Output :
Value of num = 8.450000
Value of num on Type casting = 8

Each of the C operators have a precedence or hierarchy associated to
it that decides among the set of operators which is to be evaluated
first or which should precede the other.
There are distinct levels of precedence.
The operators of same precedence are evaluated either from left to
right or right to left, depending on the level. This is called
associativity of operators.

 Precedence of an operator is its priority in an expression for evaluation.
 Operator precedence is why the expression 5 + 3 * 2 is calculated as 5 + (3
* 2), giving 11, and not as (5 + 3) * 2, giving 16.
 We say that the multiplication operator (*) has higher "precedence" or
"priority" than the addition operator (+), so the multiplication must be
performed first.
 Associativity is the left-to-right or right-to-left order for grouping operands
to operators that have the same precedence.
 Operator associativity is why the expression 8 - 3 - 2 is calculated as (8 - 3)
- 2, giving 3, and and not as 8 - (3 - 2), giving 7.
 We say that the subtraction operator (-) is "left associative", so the left
subtraction must be performed first. When we can't decide by operator
precedence alone in which order to calculate an expression, we must use
associativity.

Following table provides a complete list of operator, their precedence
level, and their rule of association.
Rank 1 indicates highest precedence level and 15 is the lowest.

PPS_unit_2_gtu_sem_2_year_2023_GTUU.pptx

More Related Content

Similar to PPS_unit_2_gtu_sem_2_year_2023_GTUU.pptx

Recently uploaded

PPS_unit_2_gtu_sem_2_year_2023_GTUU.pptx