Array.Sort Method (Array, Int32, Int32, IComparer)
Namespace: System
Assembly: mscorlib (in mscorlib.dll)
Parameters
- array
- Type: System.Array
The one-dimensional 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.
- comparer
- Type: System.Collections.IComparer
The IComparer implementation to use when comparing elements.
-or-
null to use the IComparable implementation of each element.
| 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. -or- The implementation of comparer caused an error during the sort. For example, comparer might not return 0 when comparing an item with itself. |
| InvalidOperationException |
comparer is null, and one or more elements in array do not implement the IComparable interface. |
If comparer is null, 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 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.
On average, this method is an O(n log n) operation, where n is length; in the worst case it is an O(n ^ 2) operation.
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.
using System; using System.Collections; public class SamplesArray { public class myReverserClass : IComparer { // Calls CaseInsensitiveComparer.Compare with the parameters reversed. int IComparer.Compare( Object x, Object y ) { return( (new CaseInsensitiveComparer()).Compare( y, x ) ); } } public static void Main() { // Creates and initializes a new Array and a new custom comparer. String[] myArr = { "The", "QUICK", "BROWN", "FOX", "jumps", "over", "the", "lazy", "dog" }; IComparer myComparer = new myReverserClass(); // Displays the values of the Array. Console.WriteLine( "The Array initially contains the following values:" ); PrintIndexAndValues( myArr ); // Sorts a section of the Array using the default comparer. Array.Sort( myArr, 1, 3 ); Console.WriteLine( "After sorting a section of the Array using the default comparer:" ); PrintIndexAndValues( myArr ); // Sorts a section of the Array using the reverse case-insensitive comparer. Array.Sort( myArr, 1, 3, myComparer ); Console.WriteLine( "After sorting a section of the Array using the reverse case-insensitive comparer:" ); PrintIndexAndValues( myArr ); // Sorts the entire Array using the default comparer. Array.Sort( myArr ); Console.WriteLine( "After sorting the entire Array using the default comparer:" ); PrintIndexAndValues( myArr ); // Sorts the entire Array using the reverse case-insensitive comparer. Array.Sort( myArr, myComparer ); Console.WriteLine( "After sorting the entire Array using the reverse case-insensitive comparer:" ); PrintIndexAndValues( myArr ); } public static void PrintIndexAndValues( String[] myArr ) { for ( int i = 0; i < myArr.Length; i++ ) { Console.WriteLine( " [{0}] : {1}", i, myArr[i] ); } Console.WriteLine(); } } /* This code produces the following output. The Array initially contains the following values: [0] : The [1] : QUICK [2] : BROWN [3] : FOX [4] : jumps [5] : over [6] : the [7] : lazy [8] : dog After sorting a section of the Array using the default comparer: [0] : The [1] : BROWN [2] : FOX [3] : QUICK [4] : jumps [5] : over [6] : the [7] : lazy [8] : dog After sorting a section of the Array using the reverse case-insensitive comparer: [0] : The [1] : QUICK [2] : FOX [3] : BROWN [4] : jumps [5] : over [6] : the [7] : lazy [8] : dog After sorting the entire Array using the default comparer: [0] : BROWN [1] : dog [2] : FOX [3] : jumps [4] : lazy [5] : over [6] : QUICK [7] : the [8] : The After sorting the entire Array using the reverse case-insensitive comparer: [0] : the [1] : The [2] : QUICK [3] : over [4] : lazy [5] : jumps [6] : FOX [7] : dog [8] : BROWN */
Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.
