Question

I have class B that has class A, this is simplified version of class A and B.

class A
{
    int x;
    int y;

    public A(int x, int y)
    {
        this.x = x;
        this.y = y;
    }   

    public A()
    {
        x = 0;
        y = 0;
    }
    ...
}

class B
{
    A a;
    public B(A a)
    {
        this.a = a;
    }

    public B()
    {
        this.a = null;
    }

    public A getA()
    {
        return a;
    }
    ...
}

And I need to compare the object a as follows.

public class MyClass
{
    public static void RunSnippet()
    {
        var a = new A(10, 20);
        var b = new B(a);
        Console.WriteLine(a == b.getA());
    }
}

The a == b.getA() was always true, but after syncing to the new A and B, now a != b.getA(). I compared the element by element of a, and b.getA() using debugger, but they seem to be the same.

Is there any way to compare the reference (the address) of a and b.getA()?
With C/C++, I could easily get the pointer value, but I don’t know how can I do that with C#.

Answer 1

You can use Object.ReferenceEquals for this. If you don’t override Equals or == it will produce the same result.

ex ReferenceEquals(a, b.getA()