C tolower function changes the letter to lowercase

C tolower function has the following syntax.

int tolower(int ch);

C tolower function is from header file ctype.h.

C tolower function returns the lowercase equivalent of ch if ch is a letter or ch is returned unchanged.

The following changes the letter Q from uppercase to lowercase and use putchar to output the result to the screen.


#include <ctype.h>
#include <stdio.h>
/* w w w.ja v a 2  s .co m*/
int main(void){

  putchar(tolower('Q'));

}

The code above generates the following result.