C# 4.0 Optional Arguments

Definition

C# 4.0 introduces the concepts of Optional Parameters, Optional arguments enable you to omit arguments for some parameters.

Parameters are optional when a default value is specified to a particular argument.

Example Program

using System;

class Program
{
    static void Main()
    {

    submitShoppingCart();


    submitShoppingCart(10);

    submitShoppingCart(10, "Laptop");


    submitShoppingCart(productName: "Laptop");


    submitShoppingCart(itemCount: 15, productName: "Laptop");

    submitShoppingCart(itemCount: 25, productName: "Desktop", eCouponCode="ecoupon123");

    }

    static void submitShoppingCart(int itemCount = 1, string productName = "Laptop", string eCouponCode = "ecoupon123", int Boolean shippingCharges = true)
    {
    Console.WriteLine("itemCount = {0}, productName = {1},
eCouponCode = {2}, shippingCharges= {3}", itemCount, productName,eCouponCode,ShippingCharges);
    }
}

Output

itemCount= 1, productName = Laptop, eCouponCode=ecoupon123, shippingCharges = True

itemCount= 10, productName = Laptop, eCouponCode=ecoupon123, shippingCharges = True

itemCount= 15, productName = Laptop, eCouponCode=ecoupon123, shippingCharges = True

itemCount= 25, productName = Desktop, eCouponCode=ecoupon123, shippingCharges = True