Add complex number using new and delete operator

Hi All,

I am learning c++, i am facing one problem adding the two objects , please help me How can i proced??


---------------------Code -------------------------------------------------------------------

#include<iosteream>

Using namespace std;

class Complex
{

double Real, imag;

public:

Complex()
{
Real = 0;
imag = 0;
}

Complex(double);
Complex(double, double);
};



void Complex ::display()
{

cout << Real << "+i" << imag << "\n" ;;

}


Complex ::Complex(double aa)
{
Real = aa;
imag = 0;
}

Complex :: Complex( double aa, double bb)
{

Real = aa;
imag = bb;

}

void main()
{

Complex *p = NULL;

Complex *a = new Complex(2, 4);
Complex *b = new Complex(2, 4);

a->display();
b->display();


//p = a->operator +(b); // Here i am trying to add the complex number ??

}


Please how can add a and b complex number.

Thanks,
Anand

Use code tags.

Use int main not void main.

Firstly,

Quote:

---

Complex *a = new Complex(2, 4);
Complex *b = new Complex(2, 4);

---

when you new an object in c++, always delete it! No exceptions!! Never!!!


Second, coming to your problem.
Complex is a class defined by you. Someone needs to define what is the outcome when you add 2 Complex objects. Since you wrote the class, and since you know what it(the class) defines, you need to define what the + operation would result in. Hence overload the operator+ and define what it would result in. For more on how to, Google.

The signature for operator + is

Code:

---

T operator + (const T &lhs, const T &rhs)
{
        T result(lhs);

        result += rhs;

        return result;
}

---

where T is the type. This is implemented as a friend function.

Also you may want to implement operator +=which will be a member function. It's usual to implement operator + in terms of operator +=

Code:

---

T &operator += (const T &rhs)
{
        // Add rhs here.

        return *this;
}

---

Notice that operator + returns a value but operator += returns a reference.

BTW Is there any good reason why you must new and delete the complex numbers? Just declaring them would be good enough.

Quote:

---

Originally Posted by JohnW@Wessex

BTW Is there any good reason why you must new and delete the complex numbers? Just declaring them would be good enough.

---

Of course there is no good reason. The OP should read this:

http://www.flounder.com/badprogram.h...%20reason%20to

Regards,

Paul McKenzie

Quote:

---

Originally Posted by anandtugaon

Hi All,

I am learning c++,

---

First, why are you using new and delete anyway? There is absolutely no reason to be using it for the code you posted. Here is the main() function, rewritten as a coherent C++ function.

Code:

---

int main()
{
    Complex p;
    Complex a(2, 4);
    Complex b(2, 4);

    a.display();
    b.display();

    p = a + b;
}

---

Quote:

---

Please how can add a and b complex number.

---

The operator + must be a friend function that has the following signature:

Code:

---

Complex operator +(const Complex& lhs, const Complex &rhs);

---

However, it is better to write operator + in terms of the member operator +=

Code:

---

Complex::Complex& operator += (const Complex& rhs)
{
    // add rhs to this
    // you fill this in....
    //.....
    return *this;
}

//...
Complex operator +(const Complex& lhs, const Complex &rhs)
{
    Complex temp = lhs;
    temp += rhs;
    return temp;
}

---

Also,

1) Use code tags when posting code. The code you posted is unreadable.

2) Do not hastily type your code in the code window. There is no such include file as <iosteream>. Instead, copy the code directly from your code editor and paste it in the message, so that there are no mistakes that could mislead us.

Regards,

Paul McKenzie

Quote:

---

Originally Posted by Paul McKenzie

Of course there is no good reason. The OP should read this:

---

I didn't really think so, but I'd thought I'd give him the benefit of the doubt just in case there was a lot more to his application than was actually posted.