c语言strlen的返回值,strlen函数在c++中

写个程序验证：

#include <string.h>
#include <stdio.h>
#include <conio.h>
#include <dos.h>

void main( void )
{
char str[61] = "How are you?";
char * pstr=str;
int len;
//len = strlen (str);
len = strlen( pstr );
printf( "'%s' is %d characters longn", str, len );
}