Reference, output and value parameters. - CSharp Custom Type

CSharp examples for Custom Type:Method Parameter

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Description

Reference, output and value parameters.

Demo Code

using System;/*from  ww w  .  ja  v a  2 s.c  o  m*/
class MainClass
{
   static void Main()
   {
      int y = 5; // initialize y to 5
      int z; // declares z, but does not initialize it
      Console.WriteLine($"Original value of y: {y}");
      Console.WriteLine("Original value of z: uninitialized\n");
      // pass y and z by reference
      SquareRef(ref y); // must use keyword ref
      SquareOut(out z); // must use keyword out
      Console.WriteLine($"Value of y after SquareRef: {y}");
      Console.WriteLine($"Value of z after SquareOut: {z}\n");
      // pass y and z by value
      Square(y);
      Square(z);
      Console.WriteLine($"Value of y after Square: {y}");
      Console.WriteLine($"Value of z after Square: {z}");
   }
   // uses reference parameter x to modify caller's variable
   static void SquareRef(ref int x)
   {
      x = x * x; // squares value of caller's variable
   }
   // uses output parameter x to assign a value to an uninitialized variable
   static void SquareOut(out int x)
   {
      x = 6; // assigns a value to caller's variable
      x = x * x; // squares value of caller's variable
   }
   // parameter x receives a copy of the value passed as an argument, so this method cannot modify the caller's variable
   static void Square(int x)
   {
      x = x * x;
   }
}

Result


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