C – If-Else Statement

The if-else statements are used to run specific code based on condition. The if statement executes a statement if a specified condition is true. If the condition is false, another statement can be executed. Basically, there are 4 types of if statements.

if statement
if-else statement
if-else-if ladder statement
nested if statement

1. if Statement

An if statement evaluates the expression written inside the parenthesis.

if (Expression) 
{
   // statement block
}

If the expression returns true, The if statement block will be executed. If the expression return false (zero), the statement block will be skipped.

Example: if Statement

The following program with input a number from the user and check if the number is less than 10.

// The C programme to input number from user
// Check if number is less than 10

#include <stdio.h>
void main()
{
    int num;

    printf("Enter an number: ");
    scanf("%d", &num);

    if (num < 10)
    {
        printf("num is less than 10);
    }
}

// The C programme to input number from user

// Check if number is less than 10

#include <stdio.h>

void main()

{

int num;

printf("Enter an number: ");

scanf("%d", &num);

if (num < 10)

{

printf("num is less than 10);

}

2. if-else Statement

An if statement evaluates the expression and execute the statements based on results.

if (Expression) 
{
   // if statement block
}
else
{
   // else statement block
}

If the expression returns true, The if statement block will be executed. If the expression return false (zero), the else statement block will be executed.

Example: if-else Statement

The following program with input a number from the user and check if the number is less than 10.

// The C programme to input number from user
// Check if given number is even or odd

#include <stdio.h>
void main()
{
    int num;

    printf("Enter an number: ");
    scanf("%d", &num);

    if(num % 2 == 0)
        printf("%d is even number", num);
    else
        printf("%d is odd number", num);
}

// The C programme to input number from user

// Check if given number is even or odd

#include <stdio.h>

void main()

{

int num;

printf("Enter an number: ");

scanf("%d", &num);

if(num % 2 == 0)

printf("%d is even number", num);

else

printf("%d is odd number", num);

}

3. if-else-if Statement

An if statement evaluates the expression and executes the statements based on results.

if (Expression) 
{
   // statement 1
}
else if (Expression)
{
   // statement 2
}

If the expression returns true, The statement 1 block will be executed. If the expression return false (zero), the control go to else and again evaluates a expression.

Example: if-else-if Statement

The following program with input a number from the user and check if the number is less than 10.

// The C programme to input 2 numbers from user
// Check which number is greater than other
#include <stdio.h>
void main()
{
    int num1;
    int num2;

    printf("Enter first number: ");
    scanf("%d", &num1);

    printf("Enter second number: ");
    scanf("%d", &num2);

    if(num1 > num2 )
    {
        printf("%d is greater than %d number", num1, num2);
    }
    else if(num2 > num1 )
    {
        printf("%d is odd number", num2, num1);
   }
}

// The C programme to input 2 numbers from user

// Check which number is greater than other

#include <stdio.h>

void main()

{

int num1;

int num2;

printf("Enter first number: ");

scanf("%d", &num1);

printf("Enter second number: ");

scanf("%d", &num2);

if(num1 > num2 )

{

printf("%d is greater than %d number", num1, num2);

}

else if(num2 > num1 )

{

printf("%d is odd number", num2, num1);

}

else, if

C Programming

C – if-else

C – If-Else Statement

1. if Statement

2. if-else Statement

3. if-else-if Statement