lastMatch Property ($&)

Artikel
11/16/2012

Returns the last matched characters from any regular expression search. Read-only.

RegExp.lastMatch

Arguments

RegExp
Required. The global RegExp object.

Remarks

The initial value of the lastMatch property is an empty string. The value of the lastMatch property changes whenever a successful match is made.

Note

The properties of the RegExp object are not available when a program is running in fast mode, the default for JScript. To compile a program that uses these properties from a command prompt, you must turn off the fast option by using /fast-. It is not safe to turn off the fast option in ASP.NET because of threading issues.

The short form for the lastMatch property is $&. The expressions RegExp["$&"] and RegExp.lastMatch can be used interchangeably.

Example

The following example illustrates the use of the lastMatch property:

// Create the regular expression pattern.
var re = new RegExp("d(b)(d)","ig");
var str = "cdbBdbsbdbdz";

// Perform the search.
var arr = re.exec(str);

// Create the output.
var s = "" 
s += "$1: " + RegExp.$1 + "\n";
s += "$2: " + RegExp.$2 + "\n";
s += "$3: " + RegExp.$3 + "\n";
s += "input: " + RegExp.input + "\n";
s += "lastMatch: " + RegExp.lastMatch + "\n";
s += "leftContext: " + RegExp.leftContext + "\n";
s += "rightContext: " + RegExp.rightContext + "\n"; 
s += "lastParen: " + RegExp.lastParen + "\n";

The output of this program is as follows:

$1: bB
$2: d
$3: 
input: cdbBdbsbdbdz
lastMatch: dbBd
leftContext: c
rightContext: bsbdbdz
lastParen: d

Requirements

Version 5.5

Applies To:

RegExp Object

Change History

Date	History	Reason
July 2009	Modified example.	Content bug fix.
July 2009	Modified note about the /fast option.	Content bug fix.
March 2009	Modified example and information about the /fast option.	Information enhancement.

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