RegExp

Overview

The RegExp object in JavaScript provides powerful tools for pattern matching and text processing. It allows developers to define patterns for searching and manipulating strings, supporting modifiers such as global searches, case-insensitivity, and multiline matching. Key properties include the pattern source, flags indicating active modifiers, and the index position for the next match.

Core functionality includes the exec() method, which searches for a pattern and returns the matched value while keeping track of the match position, and the test() method, which checks if a pattern exists in a string, returning a boolean result.

For more information see: RegExp (MDN).

Properties Summarized

Type	Name	Summary
Boolean	global	Specifies if the "g" modifier is set.
Boolean	ignoreCase	Specifies if the "i" modifier is set.
Number	lastIndex	An integer specifying the index at which to start the next match.
Boolean	multiline	Specifies if the "m" modifier is set.
String	source	The text used for pattern matching.

Methods Summarized

Type	Name	Summary
String	exec(string)	Search a string for a specified value.
Boolean	test(string)	Search a string for a specified value.

Properties Detailed

global

Specifies if the "g" modifier is set.

Type Boolean

Sample

var str = 'Visit www.servoy.com';
var patt1 = new RegExp('www');
application.output(patt1.global);

ignoreCase

Specifies if the "i" modifier is set.

Type Boolean

Sample

var str = 'Visit www.servoy.com';
var patt1 = new RegExp('www');
application.output(patt1.ignoreCase);

lastIndex

An integer specifying the index at which to start the next match.

Type Number

Sample

var str = 'The rain in Spain stays mainly in the plain';
var patt1 = new RegExp('ain', 'g');
patt1.test(str);
application.output('Match found. index now at: ' + patt1.lastIndex);

multiline

Specifies if the "m" modifier is set.

Type Boolean

Sample

var str = 'Visit www.servoy.com';
var patt1 = new RegExp('www','m');
application.output(patt1.multiline);

source

The text used for pattern matching.

Type String

Sample

var str = 'Visit www.servoy.com';
var patt1 = new RegExp('www.','g');
application.output('The regular expression is: ' + patt1.source);

Methods Detailed

exec(string)

Search a string for a specified value. Returns the found value and remembers the position.

Parameters

• Object string ;

Returns: String A String representing the found value.

Sample

var str='Visit www.servoy.com';
var patt=new RegExp('servoy');
application.output(patt.exec(str));

test(string)

Search a string for a specified value. Returns true or false.

Parameters

• Object string ;

Returns: Boolean true if a match was found in the string. false otherwise.

Sample

var str='Visit www.servoy.com';
var patt=new RegExp('soft');
application.output(patt.test(str)==true);
patt.compile('servoy');
application.output(patt.test(str)==true)

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