C program to print all even numbers between 1 to n using while loop

Write a C program to enter any number from user and print all even numbers between 1 to n using while loop. C program to display even number in a given range using while loop. How to generate even numbers from 1 to n using while loop in C programming.

Example:
Input value of n: 10
Output even numbers between 1 to 10: 2, 4, 6, 8, 10

Also do check this program using for loop - C program to print all even numbers between 1 to n using for loop.

Required knowledge

Basic C programming, If else, While loop

Even numbers

Numbers that are exactly divisible by 2 are called as even numbers. Example: 2, 4, 6, 8, 10 are the first 5 even numbers.

Before moving to this program you must know how to check whether a number is even or odd using if else.

Program to print even numbers using if

/**
 * C program to print all even numbers from 1 to n
 */

#include <stdio.h>

int main()
{
    int i, n;
  
    //Reads the upper limit of even number from user
    printf("Print all even numbers till: ");
    scanf("%d", &n);

    printf("All even numbers from 1 to %d are: \n", n);

    /*
     * Starts loop counter from 1, increments by 1 till i<=n
     */
    i=1;
    while(i<=n)
    {
        /* Check even condition before printing */
        if(i%2==0)
        {
            printf("%d\n", i);
        }

        i++;
    }

    return 0;
}

Program to display even numbers without using if statement

/**
 * C program to display all even numbers from 1 to n using while loop
 */

#include <stdio.h>

int main()
{
    int i, n;
  
    //Reads the upper limit of even number from user
    printf("Print all even numbers till: ");
    scanf("%d", &n);

    printf("All even numbers from 1 to %d are: \n", n);

    i=2; //Since 2 is the first even number
    while(i<=n)
    {
        printf("%d\n", i);

        /*
         * Adding 2 to current even number will give next even number
         */
        i += 2;
    }

    return 0;
} 

Happy coding ;)