Regex.Replace Method (String, String, String)

Replaces all occurrences of matches defined by the regular expression with a replacement string, starting at the first character in the input string.

Namespace: System.Text.RegularExpressions
Assembly: System (in system.dll)

public static string Replace (
	string input,
	string pattern,
	string replacement
public static String Replace (
	String input, 
	String pattern, 
	String replacement
public static function Replace (
	input : String, 
	pattern : String, 
	replacement : String
) : String



The string to modify.


The regular expression pattern to match.


The replacement string.

Return Value

The modified character string.

Substitutions are allowed only within a replacement pattern. For similar functionality within a regular expression, use a backreference such as \1.

Character escapes and substitutions are the only special constructs recognized in a replacement pattern. All other syntactic constructs are allowed in regular expressions only and not recognized in replacement patterns. For example, the replacement pattern a*${test}b inserts the string "a*" followed by the substring matched by the "test" capturing group, if any, followed by the string "b". The * character is not recognized as a metacharacter within a replacement pattern. Similarly, $-patterns are not recognized within a regular expression matching pattern. Within a regular expression, $ denotes the end of the string. Other examples are: $123 substitutes the last substring matched by group number 123 (decimal), and ${name} substitutes the last substring matched by a (?<name>) group.

The static Replace methods are equivalent to constructing a Regex object with the specified regular expression pattern and calling the instance method Replace. The static methods are provided to allow an isolated, single use of a regular expression without explicitly creating a Regex object.

Windows 98, Windows 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 .NET Framework does not support all versions of every platform. For a list of the supported versions, see System Requirements.

.NET Framework

Supported in: 2.0, 1.1, 1.0

.NET Compact Framework

Supported in: 2.0, 1.0