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Path.GetExtension Method

Returns the extension of the specified path string.

Namespace: System.IO
Assembly: mscorlib (in mscorlib.dll)

public static string GetExtension (
	string path
)
public static String GetExtension (
	String path
)
public static function GetExtension (
	path : String
) : String
Not applicable.

Parameters

path

The path string from which to get the extension.

Return Value

A String containing the extension of the specified path (including the "."), a null reference (Nothing in Visual Basic), or Empty. If path is a null reference (Nothing in Visual Basic), GetExtension returns a null reference (Nothing in Visual Basic). If path does not have extension information, GetExtension returns Empty.

Exception typeCondition

ArgumentException

path contains one or more of the invalid characters defined in GetInvalidPathChars.

The extension of path is obtained by searching path for a period (.), starting with the last character in path and continuing toward the start of path. If a period is found before a DirectorySeparatorChar or AltDirectorySeparatorChar character, the returned string contains the period and the characters after it; otherwise, Empty is returned.

For a list of common I/O tasks, see Common I/O Tasks.

The following code example demonstrates using the GetExtension method on a Windows-based desktop platform.

string fileName = @"C:\mydir.old\myfile.ext";
string path = @"C:\mydir.old\";
string extension;

extension = Path.GetExtension(fileName);
Console.WriteLine("GetExtension('{0}') returns '{1}'", 
    fileName, extension);

extension = Path.GetExtension(path);
Console.WriteLine("GetExtension('{0}') returns '{1}'", 
    path, extension);

// This code produces output similar to the following:
//
// GetExtension('C:\mydir.old\myfile.ext') returns '.ext'
// GetExtension('C:\mydir.old\') returns ''

String fileName = "C:\\mydir.old\\myfile.ext";
String path = "C:\\mydir.old\\";
String extension;

extension = Path.GetExtension(fileName);
Console.WriteLine("GetExtension('{0}') returns '{1}'",
    fileName,extension);

extension = Path.GetExtension(path);
Console.WriteLine("GetExtension('{0}') returns '{1}'", path,extension);

var fileName : String = "C:\\mydir.old\\myfile.ext";
var path : String = "C:\\mydir.old\\";
var extension : String;

extension = Path.GetExtension(fileName);
Console.WriteLine("GetExtension('{0}') returns '{1}'", 
                  fileName, extension);

extension = Path.GetExtension(path);
Console.WriteLine("GetExtension('{0}') returns '{1}'", 
                  path, extension);

Windows 98, Windows Server 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.

.NET Framework

Supported in: 3.0, 2.0, 1.1, 1.0

.NET Compact Framework

Supported in: 2.0, 1.0

XNA Framework

Supported in: 1.0

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