put a while in a function c code example

Example 1: WHILE loop in c

while( a < 20 ) {
      printf("value of a: %d\n", a);
      a++;
   }

Example 2: while loop in c

//While loop, for the largest of two numbers.
#include <stdio.h>
int main(){
	int a, b;
    printf("Enter Values a and b:\n");
    scanf("%d %d", &a, &b);
    while (a < b){
    	printf("%d is greater than %d\n", b, a);
      	printf("Enter Values a and b:\n");
      	scanf("%d %d", &a, &b);
    }
    	printf("%d is greater than %d\n", a, b);
      
}