# 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

Input value of n: 10

Output

Even numbers between 1 to 10: 2, 4, 6, 8, 10

## Required knowledge

Basic C programming, If else, While loop

Before moving to this program you must know.

Read more – How to check whether a number is even or odd.

## Program to print even numbers using if else

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

#include <stdio.h>

int main()
{
int i, n;

// Input 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;
}

Note: As I already mentioned the above method of generating even numbers is not optimal and takes more time to execute. Hence you must use the below method to generate even numbers.

## 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;

// Input 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;
}

Check this program using for loop.

Output

Print all even numbers till: 100
All even numbers from 1 to 100:
2
4
6
8
10
12
14
16
18
20
22
24
26
28
30
32
34
36
38
40
42
44
46
48
50
52
54
56
58
60
62
64
66
68
70
72
74
76
78
80
82
84
86
88
90
92
94
96
98
100

Happy coding ðŸ˜‰