Java Reference
In-Depth Information
The
RegExp
Object
A
regular expression
(or RegExp, for short) is a pattern that can be used to search or modify
strings. A common use case is "find and replace" type operations. For example, say you were
looking for any word ending in "ing," you could use the regular expression
/\w+ing/
.
If that example looks a bit confusing, don't worry, it will become clear as we move through
this section. Regular expressions can look a little strange; in fact, they're something of a dark
art that could easily fill a whole book! They are certainly useful when manipulating text
strings, though, so we'll introduce some of the basics here and recommend that you carry out
further reading once you've finished this topic.
Here are a couple of resources for the curious:
Creating Regular Expressions
There are two ways to create a regular expression. The first, and preferred way, is to use the
literal notation of writing the regular expression between forward slashes that we've already
seen:
var pattern = /\w+ing/;
Alternatively, you can create a new instance of the
RegExp
object using the
new
operator:
var pattern = new RegExp('\w+ing');
This permits you to create regular expressions using strings.
