Skip to Main Content
JavaScript: The Definitive Guide, Fourth Edition
book

JavaScript: The Definitive Guide, Fourth Edition

by David Flanagan
November 2001
Intermediate to advanced content levelIntermediate to advanced
936 pages
68h 43m
English
O'Reilly Media, Inc.
Content preview from JavaScript: The Definitive Guide, Fourth Edition

Name

RegExp.lastIndex — the starting position of the next match

Availability

JavaScript 1.2; JScript 5.5; ECMAScript v3

Synopsis

                  regexp.lastIndex

Description

lastIndex is a read/write property of RegExp objects. For regular expressions with the g attribute set, it contains an integer that specifies the character position immediately following the last match found by the RegExp.exec( ) and RegExp.test( ) methods. These methods use this property as the starting point for the next search they conduct. This allows you to call those methods repeatedly, to loop through all matches in a string. Note that lastIndex is not used by RegExp objects that do not have the g attribute and do not represent global patterns.

This property is read/write, so you can set it at any time to specify where in the target string the next search should begin. exec( ) and test( ) automatically reset lastIndex to 0 when they fail to find a match (or another match). If you begin to search a new string after a successful match of some other string, you have to explicitly set this property to 0.

Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
and much more.
Start your free trial

You might also like

JavaScript: A Beginner's Guide, Fourth Edition, 4th Edition

JavaScript: A Beginner's Guide, Fourth Edition, 4th Edition

John Pollock
Coding with JavaScript For Dummies

Coding with JavaScript For Dummies

Chris Minnick, Eva Holland

Publisher Resources

ISBN: 0596000480Supplemental ContentCatalog PageErrata