Polymorphism?

I'm a newbie here, when it comes to C++, but i know how to make functions that overloads each other. I've heard you can overload operators too for isntance

Code:

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Cls1 Obj1;
Cls2 Obj2;

Obj1 = Obj2;
Obj1 = Obj1 + Obj2 / Obj1 * Obj1;
Obj1 += Obj2;

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how do i achieve this?

Maybe you can use this:

Code:

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Listing 10.8. Overloading operator++.

1:    // Listing 10.8
2:    // The Counter class
3:
4:    typedef unsigned short  USHORT;
5:    #include <iostream.h>
6:
7:    class Counter
8:    {
9:        public:
10:          Counter();
11:          ~Counter(){}
12:          USHORT GetItsVal()const { return itsVal; }
13:          void SetItsVal(USHORT x) {itsVal = x; }
14:          void Increment() { ++itsVal; }
15:          void operator++ () { ++itsVal; }
16:
17:      private:
18:          USHORT itsVal;
19:
20:    };
21:
22:    Counter::Counter():
23:    itsVal(0)
24:    {};
25:
26:    int main()
27:    {
28:      Counter i;
29:      cout << "The value of i is " << i.GetItsVal() << endl;
30:      i.Increment();
31:      cout << "The value of i is " << i.GetItsVal() << endl;
32:      ++i;
33:      cout << "The value of i is " << i.GetItsVal() << endl;
34:    return 0;
35: }
Output: The value of i is 0
The value of i is 1
The value of i is 2

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Thanks, i appreciate that much :) Can you explain how i would go doing these operations i mentioned?

Code:

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15:          void operator++ () { ++itsVal; }

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so if this works for Obj1++ then how do i get Obj1 = Obj1 + Obj2; to work?

#include <iostream.h>

class number
{
public:
int n;
number() {n = 1;}
number operator+ (number);
};

number number::operator+ (number N)
{
cout << "\noperator+() function is working ";
number T;
T.n = N + N.n;
return T;
}

void main()
{
number x,y,z;

Z = X.operator+(Y) //Explicit
cout << Z.n; //2

Z = X + Y; //Implicit
cout << Z.n; //2

Z = Z + X + Y; //Chain of calls
cout << Z.n; //4
}

Quote:

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Originally posted by kedaman
I'm a newbie here, when it comes to C++

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Join the party kedaman.
For C++, we have to look to parksie, vlatko, and a few others :rolleyes:.

I wish C++ coding was as easy as VB.
I'm still learning..still reading the tutorials at http:///www.cprogramming.com :o.

Thanks, Psy, very nice of you helping me :) thanks for the tutorial Matt ;) i'll have a look at it. Maybe i should add parksie to my ICQ list?

Here is a sample of how to overload the + operator.

Code:

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1:    // Listing 10.14
2:    //Overload operator plus (+)
3:
4:    typedef unsigned short  USHORT;
5:    #include <iostream.h>
6:
7:    class Counter
8:    {
9:    public:
10:      Counter();
11:      Counter(USHORT initialValue);
12:      ~Counter(){}
13:      USHORT GetItsVal()const { return itsVal; }
14:      void SetItsVal(USHORT x) {itsVal = x; }
15:      Counter operator+ (const Counter &);
16:    private:
17:      USHORT itsVal;
18:    };
19:
20:    Counter::Counter(USHORT initialValue):
21:    itsVal(initialValue)
22:    {}
23:
24:    Counter::Counter():
25:    itsVal(0)
26:    {}
27:
28:    Counter Counter::operator+ (const Counter & rhs)
29:    {
30:      return Counter(itsVal + rhs.GetItsVal());
31:    }
32:
33:    int main()
34:    {
35:      Counter varOne(2), varTwo(4), varThree;
36:      varThree = varOne + varTwo;
37:      cout << "varOne: " << varOne.GetItsVal()<< endl;
38:      cout << "varTwo: " << varTwo.GetItsVal() << endl;
39:      cout << "varThree: " << varThree.GetItsVal() << endl;
40:
41:    return 0;
42: }

Output: varOne: 2
varTwo: 4
varThree: 6

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Quote:

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Maybe i should add parksie to my ICQ list?

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If you want. I'm 91747330 :)

:p Well good, now i have someone who i can ask anything about :)

Well...C++ related anyway :rolleyes: ;)

Well, here's something related, about inheritance :)
Is it possible for a class to inherit two other classes?
I was thinking about letting a windowcomponent inhering both visualcomponent and a scriptcomponent.

Most things are possible. That of course depends on whether your brain explodes while debugging it ;).

Code:

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class MyClass : public WindowClass, public ScriptClass {
    MyClass() { }
    virtual ~MyClass() { }

    int WindowClassFunction() { } // Overload from WindowClass

    int ScriptClassFunction() { } // Overload from ScriptClass
};

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You also inherit any data members. Although I think you get an error (maybe a warning) if two classes you inherit from have two identical members.

Thanks parksie, that was i was hoping for :)