W3Schools.com


  
HOME HTML CSS XML JAVASCRIPT ASP PHP SQL MORE... REFERENCES | EXAMPLES | FORUM | ABOUT

JavaScript RegExp Object

« Previous Next Chapter »

RegExp, is short for regular expression.


Complete RegExp Object Reference

For a complete reference of all the properties and methods that can be used with the RegExp object, go to our complete RegExp object reference.

The reference contains a brief description and examples of use for each property and method!


What is RegExp?

A regular expression is an object that describes a pattern of characters.

When you search in a text, you can use a pattern to describe what you are searching for.

A simple pattern can be one single character.

A more complicated pattern can consist of more characters, and can be used for parsing, format checking, substitution and more.

Regular expressions are used to perform powerful pattern-matching and "search-and-replace" functions on text.

Syntax

var txt=new RegExp(pattern,modifiers);

or more simply:

var txt=/pattern/modifiers;
  • pattern specifies the pattern of an expression
  • modifiers specify if a search should be global, case-sensitive, etc.

RegExp Modifiers

Modifiers are used to perform case-insensitive and global searches.

The i modifier is used to perform case-insensitive matching.

The g modifier is used to perform a global match (find all matches rather than stopping after the first match).

Example 1

Do a case-insensitive search for "w3schools" in a string:

var str="Visit W3Schools";
var patt1=/w3schools/i;

The marked text below shows where the expression gets a match:

Visit W3Schools

Try it yourself »

Example 2

Do a global search for "is":

var str="Is this all there is?";
var patt1=/is/g;

The marked text below shows where the expression gets a match:

Is this all there is?

Try it yourself »

Example 3

Do a global, case-insensitive search for "is":

var str="Is this all there is?";
var patt1=/is/gi;

The marked text below shows where the expression gets a match:

Is this all there is?

Try it yourself »


test()

The test() method searches a string for a specified value, and returns true or false, depending on the result.

The following example searches a string for the character "e":

Example

var patt1=new RegExp("e");
document.write(patt1.test("The best things in life are free"));

Since there is an "e" in the string, the output of the code above will be:

true

Try it yourself »


exec()

The exec() method searches a string for a specified value, and returns the text of the found value. If no match is found, it returns null.

The following example searches a string for the character "e":

Example 1

var patt1=new RegExp("e");
document.write(patt1.exec("The best things in life are free"));

Since there is an "e" in the string, the output of the code above will be:

e

Try it yourself »

« Previous Next Chapter »


Stylus Studio® XML Development Environment

stylus

Stylus Studio® 2011 XML Enterprise Suite raises the bar for productivity in XML development tools. Millions of XML developers and data integration specialists turn to Stylus Studio's comprehensive and intuitive XML toolset to tackle today's advanced XML data transformation and aggregation challenges.

stylus
  • XML Pipeline Editor, Debugger and Code Generator
  • DataDirect XML Converters
  • XQuery Mapper, Editor, Debugger, and Profiler
  • XSLT Mapper, Editor, Debugger, Designer, and Profiler
  • Java and C# for .Net Code Generation
  • XML Schema Designer With Documentation Generator
  • XML Editor With Full XPath Integration

Download a free trial now



 
WEB HOSTING
Best Web Hosting
PHP MySQL Hosting
Top 10 Web Hosting
UK Reseller Hosting
Web Hosting
Top Web Hosting
$1 Domain Sale
WEB BUILDING
XML Editor – Free Trial!
FREE Flash Website
6,000+ HTML Templates
Download now (FREE)
Advertise on Google
Stand out on Google search and maps Click Here
W3SCHOOLS EXAMS
Get Certified in:
HTML, CSS, JavaScript, XML, PHP, and ASP
W3SCHOOLS BOOKS
New Books:
HTML, CSS
JavaScript, and Ajax
STATISTICS
Browser Statistics
Browser OS
Browser Display
SHARE THIS PAGE