C语言基础：通过指针遍历字符数组转换字符串为大写

#include <stdio.h>
#include <ctype.h>
 
char *string_uppercase(char *string)
 {
   char *starting_address;
 
   starting_address = string;
 
   while (*string)
     toupper(*string++);
 
   return(starting_address);
 }
 
int main(void)
 {
   char *title = "Jamsa's 1001 C/C++ Tips";
   char *string;
 
   string = string_uppercase(title);
   printf("%sn",string);
 
   printf("%sn",string_uppercase("Arrays and Pointers"));
 
return 1;
 }