Question

I have a string which could contain several different values, among them are.

EDITED for clarity:
var test could equal FW21002-185 or FW21002-181-0001 or abcdefg or 245-453-654 or FW21002-181-00012

I would like to remove all characters after and including the last – only if that string contains four characters after the last dash. So in the above strings examples, the only one that should be changed is the second one to “FW21002-181” All others would remain as they are.

How would I do this in JavaScript. Regex is ok as well. Thanks.

Answer 1

A regex to do this would be

var chopped = test.replace(/-[^-]{4,}$/, '-');

(assuming you want that “-” at the end). (Oh also this is intended to match 4 or more trailing characters – if you want exactly four, just get rid of the comma in {4,}.)