While loops check the test condition at the top of the loop

Introduction

The body of the loop will not execute if the condition is false.

The following pad() function adds spaces to the end of a string to fill the string to a predefined length.

If the string is already at the desired length, no spaces are added.

Demo Code

#include <stdio.h>
#include <string.h>

void pad(char *s, int length);

int main(void)
{

   char str[80];//  www  .  j a  va 2 s.  c om

   strcpy(str, "this is a test");
   pad(str, 40);
   printf("%d", strlen(str));

   return 0;
}

/* Add spaces to the end of a string. */
void pad(char *s, int length)
{
   int l;

   l = strlen(s); /* find out how long it is */

   while (l < length) {

      s[l] = ' '; /* insert a space */
      l++;
   }
   s[l] = '\0'; /* strings need to be terminated in a null */
}

While loops check the test condition at the top of the loop - C Statement

Introduction

Demo Code

Result

Related Tutorials