Indexers are a kind of properties. Indexers let you use array notation on objects that are instances of your own classes.

This is a simple and somewhat artificial example of the use of indexers. It is illustrated how three individual variables d, e, and f in class A can be accessed as a[1], a[2], a[3], where a is an instance of class A.

This is example shows a fine and realistic use of an indexer. The indexer accesses the individual bits in a bit array. The bit array is represented as a (relatively small) array of 32 bit integers. This example is taken from the C# language specification. Please consult the text book version for an explanation of the details.