program to print/display all even numbers lying between 1 to n natural numbers.

first with while loop
//program  to print/display all even numbers lying between 1 to n natural numbers.
#include<stdio.h>
#include<conio.h>
void main()
{
int k=1,n;
printf("enter value of 'n'\n");
scanf("%d",&n);
while(k<=n)
   {
      if(k%2==0)
      {      printf("%d,",k);
      }
    k++;
   }
getch();
}

now with for loop

//program  to print/display all even numbers lying between 1 to n natural numbers.
#include<stdio.h>
#include<conio.h>
void main()
{
int k,n;
printf("enter value of 'n'\n");
scanf("%d",&n);
for(k=1;k<=n;k++)
   {
     if(k%2==0)
      {      printf("%d,",k);
      }
    
   }
getch();
}

now using do..while loop

//A program  to print/display 1 to n natural numbers.
#include<stdio.h>
#include<conio.h>
void main()
{
int k=1,n;
printf("enter value of 'n'\n");
scanf("%d",&n);
do
  {
       if(k%2==0)
       {
          printf("%d,",k);
      } 
         k++;

   }
   while(k<=n);
getch();
}


We can also use some other methods as shown below using different loop.

//program  to print/display all even numbers lying between 1 to n natural numbers.
#include<stdio.h>
#include<conio.h>
void main()
{
int k=0,n;
printf("enter value of 'n'\n");
scanf("%d",&n);
while(k<=n)
   {
      printf("%d,",k);
      
    k=k+2;
   }
getch();
}
You now try same using other loops.