C# Out Parameter

This method is Passing Parameters by Output. Unlike other methods that return only a single value from the method, the Out Parameter can return multiple values from a function.

They are similar to reference type, except the data are transferred out rather than into it. C# provide out keyword for the out parameter type.

Example: C# Out Parameter

using System;

namespace Programs
{
   class Swapping
   {
      // function (user-defined)
      public void valueFunc(out int val)
      {
         int temp = 20;
         val = temp;
      }

      //main method
      static void Main(string[] args)
      {
         Swapping swapObj = new Swapping();

         int a = 10;

         Console.WriteLine("Before calling a method, a: {0}", a);

         //calling funciton with out keyword
         swapObj.valueFunc(out a);

         Console.WriteLine("After method called, a: {0}", a);

      }
   }
}

Output:

Before calling a method, a: 10
After method called, a: 20