javascript - Case insensitive replace all

Question

I am looking for any implementation of case insensitive replacing function. For example, it should work like this:

'This iS IIS'.replaceAll('is', 'as');

and result should be:

'Thas as Ias'

Any ideas?

UPDATE:

It would be great to use it with variable:

var searchStr = 'is';
'This iS IIS'.replaceAll(searchStr, 'as');

Answer 1

Try regex:

'This iS IIS'.replace(/is/ig, 'as');

Working Example: http://jsfiddle.net/9xAse/

e.g:
Using RegExp object:

var searchMask = "is";
var regEx = new RegExp(searchMask, "ig");
var replaceMask = "as";

var result = 'This iS IIS'.replace(regEx, replaceMask);