JavaScript: The Definitive Guide, Fourth Edition

Name

RegExp.test( ) — test whether a string matches a pattern

Availability

JavaScript 1.2; JScript 3.0; ECMAScript v3

Synopsis

                  regexp.test(string)

Arguments

string

The string to be tested.

Returns

true if string contains text that matches regexp; false otherwise.

Throws

TypeError

If this method is invoked on an object that is not a RegExp.

Description

test( ) tests string to see if it contains text that matches regexp. If so, it returns true; otherwise, it returns false. Calling the test method of a RegExp r and passing it the string s is equivalent to the following expression:

(r.exec(s) != null)

Example

var pattern = /java/i;
pattern.test("JavaScript");   // Returns true
pattern.test("ECMAScript");   // Returns false

See Also

RegExp.exec( ), RegExp.lastIndex, String.match( ), String.replace( ), String.substring( ); Chapter 10