[Solved] Capitalizing a string in C

How to capitalize a C string.

#include <stdio.h>
#include <ctype.h>
int main() {
    int i = 0;
    char str[] = "foobar";
    while(str[i]) {
        putchar (toupper(str[i]));
        i++;
    }
    return(0);
}

Test it online.