Why to use OUT parameter in c#?

Usually, method or function returns a value with return keyword. A return keyword or modifier can return only one value at a time. In some scenario, C# program required to return multiple values from a single method or function. So if you want a method or function should return multiple value then you use OUT parameter.

Example:-

namespace ConsoleApplication1

{

    class Sample

    {

        public string param1, param2;

        public static void AreaOfCircle(int radius,out double area,out double perimeter)

        {

            area = 3.14 * (radius * radius);

            perimeter = 2 * 3.14 * radius;

        }

    }

  

    class Program:Factory

    {

        static  void Main(string[] args)

        {

           

            double area;

            double perimeter;

            Sample.AreaOfCircle(5, out area, out perimeter);

            Console.Write("Area Of Circle:" + area);

            Console.Write("Perimeter Of Circle:" + perimeter);

            Console.ReadKey();

        }

    }

}

Output:-

Area Of Circle: 78.5

Perimeter Of Circle: 31.4