Boolean and Static in C Programming With Examples ( Full Guide )

Boolean in C

C doesn't have a built-in bool type in older standards; conditions simply use 0 for false and any non-zero value for true. C99 introduced _Bool and the <stdbool.h> header for true boolean support.

#include <stdbool.h>
bool isValid = true;
if (isValid) {
    printf("Valid");
}

Static in C

The static keyword changes a variable or function's lifetime and/or linkage.

• Static local variable — retains its value between function calls instead of being reset.
• Static global variable — restricts the variable's visibility to the file it's declared in.
• Static function — restricts the function's visibility to the file it's declared in.

void counter() {
    static int count = 0;
    count++;
    printf("%d\n", count);
}