Question

I have a class named Employee. Now I try to define its Equals method, but I want to accept an Employee as parameter only.

So I write this code:

class MainClass
    {
        public static void Main (string[] args)
        {
            Employee e = new Employee();
            Employee e2 = new Employee();
            Console.WriteLine(Equals(e, e2));
        }

        public static Employee CreateEmployee()
        {
            return new Employee();
        }
    } 

    class Employee
    {
        public int ID;
        public bool Equals (Employee e)
        {
            Console.WriteLine("Compare!");
            return ID == e.ID;
        }
    }

But it doesn’t work! The console outputs:

false

Not what I expected:

Compare!
true

It looks like that I have to write public override bool Equals (Object), but why? Can’t C# choose the method to call by the type of parameter(s)?

Answer 1

Try changing your code to

Console.WriteLine(e.Equals(e2)); 

As you had it it was using Object.Equals Method (Object, Object)