assignment operator

[nickyeng]

class menuitem {
public:
     menuitem(string s) :  text(s) {}
     virtual ~menuitem() {}
     virtual void display() { cout << text << endl; }
private:
     string text;
};
 

I was required to write additional methods for this class:
an copy constructor
an assignment operator

So this is what i have done:
for copy constructor:

menuitem(const menuitem& m) {
      text = m.text ;
}
 

am i correct for the copy constructor?

the assignment operator, i'm not sure how to do it. any one could show it ?

thanks in advance.
fom
Nick

i'm not s

[sicarie]

class menuitem {
public:
     menuitem(string s) :  text(s) {}
     virtual ~menuitem() {}
     virtual void display() { cout << text << endl; }
private:
     string text;
};
 

I was required to write additional methods for this class:
an copy constructor
an assignment operator

So this is what i have done:
for copy constructor:

menuitem(const menuitem& m) {
      text = m.text ;
}
 

am i correct for the copy constructor?

the assignment operator, i'm not sure how to do it. any one could show it ?

thanks in advance.
fom
Nick

i'm not s

Nick-

I found this explanation of overloading the copy constructor, let me know what you think.

As for the copy constructor, the purpose of it is to return a completely separate object, with the same data. I know Java especially enforces the 'new' keyword, and I'm not sure by spot-reading your function if it will work as a copy or not - a way to check would be to have it like you do, and then change something in the new one, see if it changed the old.

[Ganon11]

Your copy constructor looks fine - it should work with no problems.

In your assignment operator, you will be setting the text fields equal to each other - just the same as your copy constructor.

The main use of the assignment operator and deconstructor is for preventing shallow copies of pointers - that is, two pointers pointing to the same data. Since you are implementing a string and not a char*, I'd have to say I don't find the addition of these operators necessary - unless, of course, this is a class assignment for practice, in which case you're stuck :).