Question

I have the following timecode I want to do a replace on:

00 04 02 01 -- > 00:04:02:01

How would I replace the space between the two digits with a colon? I have come up with \d\s\d, but that obviously includes the digits as well.

Answer 1

Capture your digits, then use them when replacing:

(\d)\s(?=\d)

replace with:

$1:

---

The following example uses JavaScript:

var str = '00 04 02 01';
str = str.replace(/(\d)\s(?=\d)/g, '$1:');

Here’s the fiddle: http://jsfiddle.net/7arUa/