char str[] = “http://www.renren.com” (长度为21)
char *p = str ;
sizeof (str ) = ?(1)
sizeof ( p ) = ?(2)
void Foo ( char str[100]){
sizeof( str ) = ?(3)
}
void *p = malloc( 100 );
sizeof ( p ) = ?(4)
22, 22, 100, 100
4, 4, 4, 4
22, 4, 4, 4
22, 4, 100, 4