`while` — C Keyword

`while` — C Keyword

The while keyword in C: a pre-test loop that repeats while a condition is true.

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`while` (C)

Repeatedly executes a statement as long as the condition evaluates to non-zero. The condition is checked before each iteration.

Syntax

while (condition) statement

Example

#include <stdio.h>

int main(void) {
    int n = 1;
    while (n <= 5) {
        printf("%d ", n);
        ++n;
    }
    /* Output: 1 2 3 4 5 */
    printf("\n");
    return 0;
}

Notes

The body may execute zero times if the condition is false initially.
while (1) is a common infinite loop idiom in C.
cppreference: while

Example in practice

int main() {
    // Pick one facility from this reference page.
    // Write the smallest program that exercises its main precondition,
    // complexity rule, or lifetime constraint before scaling up.
    return 0;
}