Array.Sort Method (Array, Int32, Int32)
Sorts the elements in a range of elements in a onedimensional Array using the IComparable implementation of each element of the Array.
Assembly: mscorlib (in mscorlib.dll)
Parameters
 array

Type:
System.Array
The onedimensional Array to sort.
 index

Type:
System.Int32
The starting index of the range to sort.
 length

Type:
System.Int32
The number of elements in the range to sort.
Exception  Condition 

ArgumentNullException  array is null. 
RankException  array is multidimensional. 
ArgumentOutOfRangeException  index is less than the lower bound of array. or length is less than zero. 
ArgumentException  index and length do not specify a valid range in array. 
InvalidOperationException  One or more elements in array do not implement the IComparable interface. 
Each element within the specified range of elements in array must implement the IComparable interface to be capable of comparisons with every other element in array.
If the sort is not successfully completed, the results are undefined.
This method uses the introspective sort (introsort) algorithm as follows:
If the partition size is fewer than 16 elements, it uses an insertion sort algorithm.
If the number of partitions exceeds 2 * LogN, where N is the range of the input array, it uses a Heapsort algorithm.
Otherwise, it uses a Quicksort algorithm.
This implementation performs an unstable sort; that is, if two elements are equal, their order might not be preserved. In contrast, a stable sort preserves the order of elements that are equal.
For arrays that are sorted by using the Heapsort and Quicksort algorithms, in the worst case, this method is an O(n log n) operation, where n is length.
The following code example shows how to sort the values in an Array using the default comparer and a custom comparer that reverses the sort order. Note that the result might vary depending on the current CultureInfo.
Available since 8
.NET Framework
Available since 1.1
Portable Class Library
Supported in: portable .NET platforms
Windows Phone Silverlight
Available since 8.0
Windows Phone
Available since 8.1