C语言 strlen()函数

size_t strlen(const char *str)

#include <stdio.h>
#include <string.h>
int main () {
   char str[50]; 
   int length;

   strcpy(str, "Welcome to Beginnersbook.com");

   //returns the number of characters in the string 
   length = strlen(str);

   printf("Length of string - %s is: %d", str, length);
   return 0;
}

Length of string - Welcome to Beginnersbook.com is: 28