O'Reilly logo

JavaScript: The Definitive Guide, 6th Edition by David Flanagan

Stay ahead with the world's most comprehensive technology and business learning platform.

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, tutorials, and more.

Start Free Trial

No credit card required

Defining Regular Expressions

In JavaScript, regular expressions are represented by RegExp objects. RegExp objects may be created with the RegExp() constructor, of course, but they are more often created using a special literal syntax. Just as string literals are specified as characters within quotation marks, regular expression literals are specified as characters within a pair of slash (/) characters. Thus, your JavaScript code may contain lines like this:

var pattern = /s$/;

This line creates a new RegExp object and assigns it to the variable pattern. This particular RegExp object matches any string that ends with the letter “s.” This regular expression could have equivalently been defined with the RegExp() constructor like this:

var pattern = new RegExp("s$");

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, interactive tutorials, and more.

Start Free Trial

No credit card required