How to pass a variable into regex in jQuery/Javascript

Question

Is there a way to pass a variable into a regex in jQuery/Javascript?

I wanna do something like:

var variable_regex = "bar";
var some_string = "foobar";

some_string.match(/variable_regex/);

In Ruby you would be able to do:

some_string.match(/#{variable_regex}/)

Found a useful post:

How can I concatenate regex literals in JavaScript?

Answer 1

It's easy:

var variable_regex = "bar";
var some_string = "foobar";

some_string.match(variable_regex);

Just lose the //. If you want to use complex regexes, you can use string concatenation:

var variable_regex = "b.";
var some_string = "foobar";

alert (some_string.match("f.*"+variable_regex));

Answer 2

Javascript doesn't support interpolation like Ruby -- you have to use the RegExp constructor:

var aString = "foobar";
var pattern = "bar";

var matches = aString.match(new RegExp(pattern));