Method overloading

Several methods can share a name if their parameter lists differ. The compiler picks one from the argument types.

Time resolved at compile timeSpace O(1)Code C#

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The idea

Overload choice happens when the code is compiled, using the declared types of the arguments. That is the opposite of overriding, where the choice is made at run time from the real object.

Code

class Printer {
    public void Print(int x) => Console.WriteLine("int " + x);
    public void Print(double x) => Console.WriteLine("double " + x);
    public void Print(string x) => Console.WriteLine("string " + x);
    public void Print(object x) => Console.WriteLine("object " + x);
}

var p = new Printer();
p.Print(5);
p.Print(2.5);
p.Print("hi");
object boxed = 5;
p.Print(boxed);   // chosen by the variable's type, not the value inside

Tips

Overloading: same name, different parameters, same class, compile time. Overriding: same signature, derived class, run time.
Return type alone cannot distinguish two overloads.

In the .NET library

Console.WriteLine itself has 18 overloads. Optional parameters (int retries = 3) often replace a pile of overloads.