using System;

using System.Collections.Generic;

public class Program

{

    public static void Main()

    {

        Console.WriteLine("--------------With Normal Methods ------------");

        Customer cust=new Customer();

        Address addr=cust.GetAddressByphoneNumber("9538");

        Console.WriteLine("Street Name: {0} , Mobile Number :{1} , Pin Code :{2}",addr.streetname,addr.mobileno,addr.pincode);

        Address addrbypin=cust.GetAddressByPostalcode(7456);

        Console.WriteLine("Street Name: {0} , Mobile Number :{1} , Pin Code :{2}",addrbypin.streetname,addrbypin.mobileno,addrbypin.pincode);

        Console.WriteLine("-------------- ------------");

        Console.WriteLine("Indexer helps to simplifies the way we  access the collection from a class");

        Console.WriteLine("--------------With indexer ------------");

        Address addrIndex1=cust[7456]; // here its called with indexer

​

        Console.WriteLine("Street Name: {0} , Mobile Number :{1} , Pin Code :{2}",addrIndex1.streetname,addrIndex1.mobileno,addrIndex1.pincode);

        Address addrIndex2=cust["9538"]; //here object act as an array. Indexer an object to be indexed in the same way as an array

    }

}

​

public class Address{

    public string streetname{get;set;}

    public string mobileno{get;set;}

    public int pincode{get;set;}

}

​

public class Customer{

    private List<Address> Customeraddresses=new List<Address>();

    public Customer(){

        Customeraddresses.Add(new Address{

            streetname="123",mobileno="9538",pincode=123

        });

        Customeraddresses.Add(new Address{

            streetname="4568",mobileno="953878",pincode=254

        });

        Customeraddresses.Add(new Address{

            streetname="8798",mobileno="312",pincode=7456

        });

    }

    //---------- methods normal

     public Address GetAddressByPostalcode(int postalcode)

        {

           foreach(Address addr in Customeraddresses)

            {

                if (addr.pincode == postalcode)

                {

                    return addr;

                }

            }

            return null;

        }

​

        public Address GetAddressByphoneNumber(string  phonenumber)

        {

            foreach (Address addr in Customeraddresses)

            {

                if (addr.mobileno == phonenumber)

                {

                    return addr;

                }

​

            }

            return null;

        }

    //--------------------------

    // indexer method 

    public Address this[int pincode]{

        get{

         foreach(Address addr in Customeraddresses)

            {

                if (addr.pincode == pincode)

                {

                    return addr;

                }

            }

            return null;

        }

    }

​

    public Address this[string phonenumber]{

        get{

              foreach (Address addr in Customeraddresses)

            {

                if (addr.mobileno == phonenumber)

                {

                    return addr;

                }

​

            }

            return null;

        }

    }

​

}