The regular expression object in JavaScript has the test() and exec() methods for regular expression problems. This object is called RegExp. The JavaScript String object has the match(), search(), replace() and split() methods for regular expression problems. The string object methods are actually better and easier to apply than the RegExp object methods. This two-part series takes a look at what you can do with them.
JavaScript String Regular Expressions - Verification of Match Occurrence (Page 2 of 5 )
If you just want to know if matching occurs between the RegExp pattern and the available string, then you have to use the test() method of the RegExp object. The following code illustrates this:
<html>
<head>
</head>
<body>
<script type="text/javascript">
var availableString = "The dog is outside the house.";
var re = /dog/
if (re.test(availableString))
alert('Matched')
else
alert('Not Matched')
</script>
</body>
</html>
The available string is "The dog is outside the house." The RegExp pattern is /dog/. The RegExp object is the re variable. The test() method takes the available string as an argument. So in the if-condition we have,
re.test(availableString)
The test() method returns true if a match occurs and false if a match does not occur. In the code, if it returns true, then the JavaScript alert’s box displays “Match.” If it returns false, then the alert box displays “Not Matched.”
Is there an equivalent String method? No. There is no equivalent string method that will simply return true or false. Whenever you just need to know whether a match occurs (true) or not (false), use the test() method of the regular expression object (RexExp).
JavaScript 
String Objects and Regular Expressions in JavaScript
