Indexers

Introduction

Indexers are special constructs that allow us to access an object’s content through an index. It adds an array-like behavior to custom types.

For example, to access the second item of an array, we use an index, 1:

int[] integerArray = new int[] { 2, 6, 8, 1 };
Console.WriteLine(integerArray[1]);

We can work with custom types in a similar fashion with indexers as we do with [] to access an array’s contents.

Syntax

In terms of syntax, indexers are like properties because they have get and set blocks. Unlike properties, they don’t have names, but are defined by a this keyword followed by []:

// Multiple parameters can be supplied
return_type this[parameter_type]
{
	get { }
	set { }
}

Usage

Let’s look at the following example for better understanding: