What is Indexer and why we use in C#.

C# has introduced  a new concept Indexer.Indexer an object to be indexed in the same way as an array.Indexer modifier can be private, public, protected or internal.The return type can be any valid C# types.Indexers in C# must have at least one parameter. Else the compiler will generate a compilation error at runtime error. Indexers are always created with this keyword.Indexers are implemented through the get and set accessors for the [ ] operator.

Syntax-----

Public <return type> this[<parameter type> index]
{
    
Get
{
        // return the value from the specified index

    }

    Set
{
       
 // set values at the specified index

    }
}

Example. 
using System;
using System.Collections;

class MyClass
{
    private string[] data = new string[5];
    public string this[int index]
    {
        get
        {
            return data[index];
        }
        set
        {
            data[index] = value;
        }
    }
}

class MyClient
{
    public static void Main()
    {
        MyClass mc = new MyClass();
        mc[0] = "Rakesh";
        mc[1] = "A3-126";
        mc[2] = "shambhu";
        mc[3] = "Pappu";
        mc[4] = "Mumbai";
        Console.WriteLine("{0},{1},{2},{3},{4}", mc[0], mc[1], mc[2], mc[3], mc[4]);
        Console.Read();
    }

}

output:
  

Share this