Regex not allow empty spaces at the end

Question

My target is to improve my regex. Regex need to everything except some special charaters, not to allow empty spaces at start, and not to allow empty spaces at the end.

^(?!\s*$)[^-\s][^`=~!@#$%^&*()[\]\/\\{}"|<>?]{3,100}$

Example:

word valid

word [space] invalid

[space] word invalid

word w valid

My regex did everything except empty space at the end. How to add this condition to forbit empty spaces at the end of regex?

out of curiosity, what is this for? i note that it allows arbitrary unicode but not common punctuation, which seems unusual — Eevee, Mar 20 '20 at 22:45

anubhava · Accepted Answer · 2020-03-20T23:06:39.870

0

You may add another negative lookahead to disallow space at the end:

^(?!\s*$)(?![^]*\s$)(?![-\s])[^`=~!@#$%^&*()[\]\/\\{}"|<>?]{3,100}$

(?![^]*\s$) is negative lookahead to assert that your regex won't allow a space at the end.

RegEx Demo

edited Mar 20 '20 at 23:06

answered Mar 20 '20 at 22:39

anubhava

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`(?!.*\s$)` is a wrong suggestion for a generic pattern that may match multiline text. It must be `(?![^]*\s$)` or `(?![\s\S]*\s$)` – Wiktor Stribiżew Mar 20 '20 at 22:59
Good point Wiktor, edited. – anubhava Mar 20 '20 at 23:06

Regex not allow empty spaces at the end

1 Answers1