Indexers

Indexers

Definition

In simple words Indexers are used for classes to act as arrays i.e. allowing classes to be indexed. 

Code

Indexers.cs

class Indexers<T>

 {

        private T[] myIndexerArray;

        public Indexers(int dataSize)

        {

            myIndexerArray = new T[dataSize];

        }

        public int getSize()

        {

            return myIndexerArray.Count(); 

        }

        public T this[int t]

        {

            get { return myIndexerArray[t]; }

            set {  myIndexerArray[t] = value; }

        }

 }

Program.cs

 static void Main(string[] args)

 {

            Indexers<int> indObj = new Indexers<int>(10);

            Console.WriteLine("Send Data: ");

            for (int i = 0; i<indObj.getSize(); i++)

            {

                Console.WriteLine("{0}. {1}", i, (1000 - i));

                indObj[i] = 1000 - i;

            }

            Console.WriteLine("\r\nGet Data: ");

            for (int i = 0; i < indObj.getSize(); i++)

            {

                Console.WriteLine("{0}. {1}", i, indObj[i]);

            }

            Console.ReadLine();

 } 

Output

Explanation

Indexer is similar to a .Net property i.e. you can user get and set for defining an indexer. Usually properties will return a state of a specific object or set it and indexers returns or sets a particular value from the object instance. In simple words it will break the instance of a given object into number of small units and indexes every part of it so it can get or set each part.

Following code use a this keyword to define an indexer:

 public T this[int t]

 {

            get { return myIndexerArray[t]; }

            set {  myIndexerArray[t] = value; }

 }