Alphanumeric, dash and underscore but no spaces regular expression check JavaScript

Question

Trying to check input against a regular expression.

The field should only allow alphanumeric characters, dashes and underscores and should NOT allow spaces.

Answer 1

Got stupid error. So post here, if anyone find it useful

1. [-\._] - means hyphen, dot and underscore
2. [\.-_] - means all signs in range from dot to underscore