How to change default custom class output [duplicate]

Question

Here's what I'm trying to get at: System.String is a class that contains an array of characters and if we were to make a string and then print it out:

String text = "Hello world!";
Console.WriteLine(text);

the output would be Hello World!

Now lets say I made my own class:

public class Output 
{
    string aProperty;
    int Count;
    ...
}

and if I were to create a new object of that type and try to write it out:

Output output = new Output();
Console.WriteLine(output);

I would get this back:

Namespace.Output

How could I change this so it always prints the content of Output.aProperty instead of the default text?

Answer 1

WriteLine method simply writes what the ToString of the object returns. ToString is defined (as virtual) in Object class, so you need to override it to have a "custom" output:

public class Output 
{
    string aProperty;
    int Count;

    public override string ToString()
    {
        return string.Format("{0}: {1}", aProperty, Count);//Or whatever you want
    }
}