Question

I would like to be sure. If I apply == operator between two operands of type class, it returns true when both variables points at the same object?
Also like in string class, to check equality based on e.g. some value, I would need to override that operator. IS that true?

Answer 1

For the second question, to give == a special meaning, you do indeed need to overload (not override) the operator (and != at the same time):

public class Test
{
    public static bool operator ==(Test t1, Test t2)
    {
        // Insert logic here, being careful of the possibility of
        // t1 and t2 being null. And don't just use if (t1 == null)
        // - it will recurse!
    }

    public static bool operator !=(Test t1, Test t2)
    {
        // Usual way of implementing
        return !(t1 == t2);
    }
}

If you’re overloading == you should almost certainly also:

• Implement IEquatable<T>
• Quite possibly make your class sealed and immutable (equality which can change is troubling)
• Override Equals(object) and GetHashCode