Exercise 9: While-Loop and Boolean Expressions

The first looping construct I'll show you is the while-loop, and it's the simplest, useful loop you could possibly use in C. Here's this exercise's code for discussion:

View Source file ex9.c Only

#include <stdio.h>

int main(int argc, char *argv[])
{
    int i = 0;
    while (i < 25) {
        printf("%d", i);
        i++;
    }

    // need this to add a final newline
    printf("\n");

    return 0;
}

From this code, and from your memorization of the basic syntax, you can see that a while-loop is simply this:

while(TEST) {
    CODE;
}

It simply runs the CODE as long as TEST is true (1). So to replicate how the for-loop works, we need to do our own initializing and incrementing of i. Remember that i++ increments i with the post-increment operator. Refer back to your list of tokens if you didn't recognize that.