Index Range C#

C# 8 introduced a new syntax for expressing a range of values using 2 System objects namely "System.Index and System.Range". 

They are useful to index/slice C# collections during the runtime of an application.

System.Index

New Index expression of C#, refers "from the end".   This feature introduces a new unary prefix hat(^) operator with the better way to index a collection from the end.

General code syntax is represented as
System.Index operator ^(int fromEnd);

Sample C# Index code is
var lastItem = array[^1];

The above code is equivalent to the tradition code of
var lastItem = array[collection.Count-1]; 

System.Range

Ranges way to access ranges / slices of any collections with an introduction of new range operation ..

The starting index of a range is inclusive, and the ending index is exclusive. Alternatively, the ending can be specified as an offset from the end.

System.Range operator ..(Index start = 0, Index end = ^0);

Sample C# Range code is
var lastItem = array [^1];
var subCollection = array[2..^5];

Above code is equivalent to the traditional way of C# code as
var lastItem = array [array.Count -1];
var subCollection = array.ToList().GetRange(2, 4);

This will help you to avoid LINQ and making your code compact and more readable.