Introduction to Programming - (C Language) - Unit : 1 – OPERATORS

 

OPERATIONS (OPERATORS)

An operator is simply a symbol that is used to perform operations. There can be many types of operations like arithmetic, logical, bitwise etc.

There are following types of operators to perform different types of operations in C language.

·        Arithmetic Operators

·        Relational Operators

·        Shift Operators

·        Logical Operators

·        Bitwise Operators

·        Ternary or Conditional Operators

·        Assignment Operator

·        Miscellaneous Operator

Arithmetic Operators in C

·     C Arithmetic operators are used to perform mathematical calculations like addition, subtraction, multiplication, division and modulus in C programs.

S.no	Arithmetic Operators	Operation	Example
1	+	Addition	A+B
2	-	Subtraction	A-B
3	*	multiplication	A*B
4	/	Division	A/B
5	%	Modulus	A%B

Example programs for C arithmetic operators

Program-1

/*program on arithmetic operators model-1*/

#include<stdio.h>

#include<conio.h>

void main()

{

            int n_1, n_2, add, sub, mul, m_div;

            float div;

            clrscr();

            printf("Enter any two numbers:");

            scanf("%d%d", &n_1, &n2);

            add = n_1 + n_2;

            sub = n_1 – n_2;

            mul = n_1 * n_2;

            div = n_1 / n_2;

            m_div = n_1 % n_2;

            printf("Addition is : %d \nSubtraction is : %d \nMultipication is : %d \nDivision       is:%f    \nModular division is : %d", add, sub, mul, div, m_div);

getch();

}

Output:

Enter any two numbers: 22

10

Addition is: 32

Subtraction is: 12

Multiplication is: 220

Division is: 2.000000

Modular division: 2

Program - 2

/*program on arithmetic operators model-2*/

#include<stdio.h>

#include<conio.h>

void main()

{

            int n_1, n_2, res;

            clrscr();

            printf("Enter any two numbers:");

            scanf("%d%d", &n_1, &n_2);

            res = n_1 + n_2;

            printf("Addition is : %d", res);

            res = n_1 – n_2;

            printf("\nSubtraction is: %d", res);

            res = n_1 * n_2;

            printf("\nMultiplication is: %d", res);

            res = n_1 / n_2;

            printf("\nDivision is: %d",res);

            res = n_1 % n_2;

            printf("\nModular division is : %d", res);

            getch(); }

Output:

Enter any two numbers: 20

10

Addition is:30

Subtraction is:10

Multiplication is:200

Division is:2

Modular division:0

Program-3

 /*program on arithmetic operators model-3*/

#include<stdio.h>

#include<conio.h>

void main()

{

            int n_1, n_2;

            clrscr();

            printf("Enter any two numbers:");

            scanf("%d%d", &n_1, &n_2);

            printf("Addition is: %d", n_1 + n_2);

            printf("\nSubtraction is: %d",n_1 – n_2);

            printf("\nMultiplication is: %d",n_1 * n_2);

            printf("\nDivision is: %d",n_1 / n_2);

            printf("\nModular division is: %d",n_1 % n_2);

            getch();

}

Output:

Enter any two numbers: 5

2

Addition is:7

Subtraction is:3

Multiplication is:10

Division is:2

Modular division:1

Assignment operators in C

·     In C programs, values for the variables are assigned using assignment operators.

·     For example, if the value “10″ is to be assigned for the variable “sum”, it can be assigned as “sum = 10;”

·     Other assignment operators in C language are given below.

Operator	Description	Example
=	assigns values from right side operands to left side operand	a=b
+=	adds right operand to the left operand and assign the result to left	a+=b is same as a=a+b
-=	subtracts right operand from the left operand and assign the result to left operand	a-=b is same as a=a-b
*=	mutiply left operand with the right operand and assign the result to left operand	a*=b is same as a=a*b
/=	divides left operand with the right operand and assign the result to left operand	a/=b is same as a=a/b
%=	calculate modulus using two operands and assign the result to left operand	a%=b is same as a=a%b

Example program for C assignment operators

/*program to swap and print two numbers using assignment operators*/

#include<stdio.h>

#include<conio.h>

void main()

{

            int n_1, n_2 , tmp;

            clrscr();

            printf("Enter any two values:");

            scanf("%d%d", &n_1, &n_2);

            tmp = n_1;

            n_1 = n_2;

            n_2 = tmp;

            printf("n_1 = %d \n n_2 = %d", n_1, n_2);

            getch();

}

Output:

Enter any two values: 10

20

n_1 = 20

n_2 = 10

Relational operators in C

·     Relational operators are used to find the relation between two variables. i.e. to compare the values of two variables in a C program.

S.no	Operators	Example	Description
1	>	x > y	x is greater than y
2	<	x < y	x is less than y
3	>=	x >= y	x is greater than or equal to y
4	<=	x <= y	x is less than or equal to y
5	==	x == y	x is equal to y
6	!=	x != y	x is not equal to y

Example program for relational operators in C

/*program on using relational operators*/

#include<stdio.h>

#include<conio.h>

void main()

{

            int n1, n2;

            clrscr();

            printf("Enter two numbers:");

            scanf("%d%d",&n1,&n2);

            printf("== -%d",n1==n2);

            printf("\n!= -%d",n1!=n2);

            printf("\n>= -%d",n1>=n2);

            printf("\n<= -%d",n1<=n2);

            printf("\n>  -%d",n1>n2);

            printf("\n<  -%d",n1<n2);

            getch();

}

Output:

Enter two numbers:20

5

== -0

!= -1

>= -1

<= -0

>   -1

<   -0

Logical operators in C

·     These operators are used to perform logical operations on the given expressions.

·     There are 3 logical operators in C language. They are, logical AND (&&), logical OR (||) and logical NOT (!).

S.no	Operators	Name	Example	Description
1	&&	logical AND	(x>5)&&(y<5)	It returns true when both conditions are true
2	||	logical OR	(x>=10)||(y>=10)	It returns true when at-least one of the condition is true
3	!	logical NOT	!((x>5)&&(y<5))	It reverses the state of the operand “((x>5) && (y<5))” If “((x>5) && (y<5))” is true, logical NOT operator makes it false

Truth table of Logical Operator

C1	C2	C1&C2	C1||C2	!C1	!C2
T	T	T	T	F	F
T	F	F	T	F	T
F	T	F	T	T	F
F	F	F	F	T	T

 Example program for logical operators in C

/*program on using logical operators*/

#include<stdio.h>

#include<conio.h>

void main()

{

            int n1,n2,n3;

            clrscr();

            printf("enter any three numbers:");

            scanf("%d%d%d",&n1,&n2,&n3);

            printf("%d",(n1!=n2)&&(n2<n3)&&(n1>n3));

            printf("\n%d",(n1!=n2)||(n2<n3)||(n1>n3));

            printf("\n%d",!(n1>n3));

            getch();

}

Output:

Enter any three numbers:20

30

10

0

1

0

Increment/Decrement Operators in C

·    Increment operators are used to increase the value of the variable by one and decrement operators are used to decrease the value of the variable by one in C programs.

·    Syntax:

 Increment operator    :     ++var_name; (or) var_name ++;

Decrement operator   :     –  - var_name; (or) var_name –  -;

·         Example:

Increment operator:     ++ i ;    i ++ ;

Decrement operator:     – - i ;    i – - ;

Difference between pre/post increment & decrement operators in C:

Below table will explain the difference between pre/post increment and decrement operators in C.

S.no	Operator type	Operator	Description
1	Pre increment	++i	Value of i is incremented before assigning it to variable i.
2	Post-increment	i++	Value of i is incremented after assigning it to variable i.
3	Pre decrement	– –i	Value of i is decremented before assigning it to variable i.
4	Post_decrement	i– –	Value of i is decremented after assigning it to variable i.

Example program for increment and decrement operators in C

/*program on using ++ and -- operators*/

#include<stdio.h>

#include<conio.h>

void main()

{

            int n;

            clrscr();

            printf("enter any number:");

            scanf("%d",&n);

            printf("%d",n++);

            printf("\n%d",++n);

            printf("\n%d",n--);

            printf("\n%d",--n);

            getch();

}

Output:

Enter any number:10

10

12

12

10

Bitwise operators

l  Bitwise operators perform manipulations of data at bit level. These operators also perform shifting of bits from right to left.

l  Bitwise operators are not applied to float or double.

Operator	Description
&	Bitwise AND
|	Bitwise OR
^	Bitwise exclusive OR
<<	left shift
>>	right shift

 

Now lets see truth table for bitwise &, | and ^

a	b	a & b	a | b	a ^ b
0	0	0	0	0
0	1	0	1	1
1	0	0	1	1
1	1	1	1	0

The bitwise shift operator, shifts the bit value. The left operand specifies the value to be shifted and the right operand specifies the number of positions that the bits in the value have to be shifted. Both operands have the same precedence.

Example :

a = 0001000

b = 2

a << b = 0100000

a >> b = 0000010

Example program for bitwise operators in C

/*program on using bitwise operators*/

#include<stdio.h>

#include<conio.h>

void main()

{

            int a,b;

            clrscr();

            printf("enter any two values:");

            scanf("%d%d",&a,&b);

            printf("%d",a&b);

            printf("\n%d",a|b);

            printf("\n%d",~a);

            printf("\n%d",a^b);

            printf("\n%d",a>>2);

            printf("\n%d",a<<2);

            getch();

}

Output:

enter any two values:13

6

4

15

-14

11

3

52

 

Conditional operator

The conditional operators in C language are known by two more names

1.     Ternary Operator

2.     ? : Operator

It is actually the if condition that we use in C language decision making, but using conditional operator, we turn the if condition statement into a short and simple operator.

The syntax of a conditional operator is :

expression 1 ? expression 2: expression 3

Explanation:

·        The question mark "?" in the syntax represents the if part.

·        The first expression (expression 1) generally returns either true or false, based on which it is decided whether (expression 2) will be executed or (expression 3)

·        If (expression 1) returns true then the expression on the left side of " : " i.e (expression 2) is executed.

·        If (expression 1) returns false then the expression on the right side of " : " i.e (expression 3) is executed.

Example program for conditional operators in C

/*program on using conditional operators*/

#include<stdio.h>

#include<conio.h>

void main()

{

            int n;

            clrscr();

            printf("enter any number:");

            scanf("%d",&n);

            (n>0)?printf("positive no."):printf("negative no.");

            getch();

}

Output:

enter any number:5

Positive no.

Special operators

Operator	Description	Example
sizeof	Returns the size of an variable	sizeof(x) return size of the variable x
&	Returns the address of an variable	&x ; return address of the variable x
*	Pointer to a variable	*x ; will be pointer to a variable x

Example program for special operators in C

/*program on using other operators*/

#include<stdio.h>

#include<conio.h>

void main()

{

            int a;

            float f;

            char ch;

            char n[20];

            double d;

            long int la;

            clrscr();

            printf("%d",sizeof(a));

            printf("\n%d",sizeof(f));

            printf("\n%d",sizeof(ch));

            printf("\n%d",sizeof(n));

            printf("\n%d",sizeof(d));

            printf("\n%d",sizeof(la));

            getch();

}

Output:

2

4

1

20

8

4