我无法使这个简单的正则表达式正常工作

Question

I'm doing this in Javascript

Here's my string: 09.22.2011-23.21-west-day

Here's what I'd like to pull out of it: 23.21

Here's my expression: /-[0-9]*\\.[0-9]*/

I get -23.21 so I'd have to run aa replace method after this to remove the "-". Is there a way to leave out the "-" with this regex or not? I never really perfected my regex skills because I usually use PHP which has the nice () capture groups.

Answer 1

Javascript has capture groups too:

var time = "09.22.2011-23.21-west-day".match(/-(\d{2}\.\d{2})/)[1]

Gives you 23.21

1. You can use \\d as a shorthand for [0-9]
2. If you know how many digits it's supposed to have, use {n} or {m,n} quantifiers. It will reduce the chance of it matching the wrong thing.

Answer 2

You can use () in JavaScript too!

s = '09.22.2011-23.21-west-day';
rx = s.match('-([0-9]*\.[0-9]*)')
alert(rx[1]);