c++ - trouble with passing a string pointer and then checking size in a constructor/method -

i'm still learning strings, i'm trying use them more often. how work? i'm not sure start (yes, object. i'm learning these atm assignment)

myclass::myclass(string* newname) {   if (newname.length() > maxnamelength) //maxnamelength = 50   {        //do stuff   } } 

here little explanation use

myclass::myclass(const std::string& newname) 

1. you not need pointer string. reference better - hence &
2. your constructor should not modifying string - tell both compiler , developer - hence const
3. do not pollute namespace - hence std::
4. do not use using std (see 3)