C# what is the point or benefit of an indexer?

Question

Doing some code reading and stumbled upon this snippet that I haven\'t seen before:

public SomeClass {
  public someInterface this[String strParameter] {
            


        

Answer 1

The "this" keyword is an indexer

from http://msdn.microsoft.com/en-us/library/6x16t2tx.aspx

"Indexers allow instances of a class or struct to be indexed just like arrays. Indexers resemble properties except that their accessors take parameters."