Method Overloading

Syntax

returnType MethodName(paramsA) { }\nreturnType MethodName(paramsB) { }

Examples

public class Calculator
{
    public int Add(int a, int b) => a + b;
    public int Add(int a, int b, int c) => a + b + c;
    public double Add(double a, double b) => a + b;
}

Calculator calc = new Calculator();
Console.WriteLine(calc.Add(2, 3));        // 5
Console.WriteLine(calc.Add(2, 3, 4));      // 9
Console.WriteLine(calc.Add(2.5, 3.5));      // 6

public class Greeter
{
    public string Greet(string name, string greeting = "Hello")
    {
        return $"{greeting}, {name}!";
    }
}

Greeter g = new Greeter();
Console.WriteLine(g.Greet("Fola"));            // Hello, Fola!
Console.WriteLine(g.Greet("Zain", "Hey"));      // Hey, Zain!

public class Pizza
{
    public void Order(string size, int toppingCount = 0, bool extraCheese = false)
    {
        Console.WriteLine($"{size} pizza, {toppingCount} toppings, extra cheese: {extraCheese}");
    }
}

Pizza pizza = new Pizza();
pizza.Order(size: "Large", extraCheese: true);  // toppingCount uses its default

Best practices

• Only overload methods when the different versions perform genuinely similar, related operations - otherwise use distinct method names for clarity
• Consider optional parameters instead of overloading when the only difference between overloads is a default value for one extra parameter
• Use named arguments at call sites for methods with several parameters, especially when skipping optional ones, to keep the call self-documenting
• Avoid overloads that are ambiguous for the compiler to resolve, such as very similar numeric type combinations

At a glance

Purpose

Applications on the .NET platform

File extension

.cs

Runs in

.NET runtime

Usually used with

.NET SDK and libraries

Specifications & further reading

• C# language reference

Related C# documentation