Get to know Indexers - CSharp Custom Type

CSharp examples for Custom Type:Indexer

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Introduction

Indexers provide a syntax for accessing elements in a class or struct which has a list or dictionary of values.

Indexers are similar to properties and are accessed via an index argument rather than a property name.

The string class has an indexer to access each of its char values via an int index:

Demo Code

using System;//  ww  w.  j  a  v  a2 s. com
class Test
{
   static void Main(){
      string s = "hello";
      Console.WriteLine (s[0]); // 'h'
      Console.WriteLine (s[3]); // 'l'
   }
}

Result

The syntax for using indexers is like that for using arrays, except that the index argument(s) can be of any type(s).

Indexers have the same modifiers as properties.

Indexers can be called null-conditionally by inserting a question mark before the square bracket

Demo Code

using System;/*from  w  w w.j a  v  a  2  s.  c  om*/
class Test
{
static void Main(){
     string s = null;
     Console.WriteLine (s?[0]);  // Writes nothing; no error.
}
}

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