If Else In C

In C programming, the if-else statement is used to make decisions in the code. It allows you to execute a block of code based on whether a condition is true or false.

Syntax:

if ( condition ) {

    // Code to execute if the condition is true

}

else {

    // Code to execute if the condition is false

}

condition: This is an expression that evaluates to either true (non-zero) or false (zero).

if block: This block of code runs if the condition is true.

Syntax:

if ( condition ) {

    // Code to execute if the condition is true

}

else block: This block of code runs if the condition is false.

How it works:

The condition is evaluated.

If the condition is true (non-zero), the code inside the if block is executed.

If the condition is false (zero), the code inside the else block is executed.

• We can use only if statements without an else statement.

• But We can not use only else statements without an if statement.

Examples:

A program to check if you can vote or not based on your age.

#include<stdio.h>

void main(){

    int age;

    printf("Enter your age: ");
    scanf("%d", &age);

    if ( age >= 18 ) {

        printf("Okay sir you can vote.\n");
        printf("Be vise while choosing your leader.\n");

    }
    else {

        printf("Nope you can vote.\n");
        printf("you should be atleast 18 year old.\n");

    }
}

Output:

cc if_else.c ; ./a.out 
Enter your age: 36
Okay sir you can vote.
Be vise while choosing your leader.

A program to check if given year is leap year or not.

#include<stdio.h>

void main(){

    int year;

    printf("Enter a Year: ");
    scanf("%d", &year);

    if ( year % 4 == 0 ) {
        printf("This is leap year.\n");
        printf("Work one more extra day.\n");
    }
    else
    {
        printf("This is not a leap year.\n");
    }
}

Output:

cc if_else.c ; ./a.out 
Enter a Year: 2020          
This is leap year.
Work one more extra day.

A program to find if a number is odd or even.

#include<stdio.h>
void main()
{
    int number;
    printf("Enter a number :");
    scanf("%d",&number);
    if ( number%2 == 0 )
        printf("n Entered number is even n");
    else
        printf("n Entered number is odd  n");
}

Output:

Enter a number : 50
Entered number is even