C# Method Parameters and Return Values

C# Parameters and Arguments

Information can be passed to methods as parameter. Parameters act as variables inside the method.

Parameters are specified after the method name, inside the parentheses. You can add as many parameters as you want, just separate them with a comma.

Syntax

void MyMethod(string fname) 
{
  Console.WriteLine(fname + " Refsnes");
}

Return Values

The void keyword, used in the previous examples, indicates that the method should not return a value. If you want the method to return a value, you can use a primitive data type (such as int, double, etc.) instead of void, and use the return keyword inside the method:

Examples

Method Parameters

Passing a string name.

using System;

class Program
{
  static void MyMethod(string fname) 
  {
    Console.WriteLine(fname + " Refsnes");
  }

  static void Main(string[] args)
  {
    MyMethod("Liam");
    MyMethod("Jenny");
    MyMethod("Anja");
  }
}

Multiple Parameters

Passing name and age.

using System;

class Program
{
  static void MyMethod(string fname, int age) 
  {
    Console.WriteLine(fname + " is " + age);
  }

  static void Main(string[] args)
  {
    MyMethod("Liam", 5);
    MyMethod("Jenny", 8);
  }
}

Return Values

Returning an integer.

using System;

class Program
{
  static int MyMethod(int x) 
  {
    return 5 + x;
  }

  static void Main(string[] args)
  {
    Console.WriteLine(MyMethod(3));
  }
}

Sum of Two Parameters

Returning the sum.

using System;

class Program
{
  static int MyMethod(int x, int y) 
  {
    return x + y;
  }

  static void Main(string[] args)
  {
    Console.WriteLine(MyMethod(5, 3));
  }
}

Named Arguments

Key-value syntax for parameters.

using System;

class Program
{
  static void MyMethod(string child1, string child2, string child3) 
  {
    Console.WriteLine("The youngest child is: " + child3);
  }

  static void Main(string[] args)
  {
    MyMethod(child3: "John", child1: "Liam", child2: "Liam");
  }
}