How to negate angular pattern/regex

Question

I have the following code

pattern="^\s+$"

I need to negate this, because as of now I got error when I put a letter, but it should only show error IF there is only white space.

I tried using ?! but it shows an error

empty or only space should return the error. If I write anything like 100space and a letter, this should be ok — YoloSwaggg, Jan 08 '19 at 07:58

The fourth bird · Answer 1 · 2019-01-08T08:14:38.017

0

If you want to use a negative lookahead (?!, you could check if from the start till the end of the string there are no whitespace characters:

pattern="^(?!\s*$)[\s\S]+$"

That will match

^ Start of string
(?!\s*$) Negative lookahead, assert that what follows is not 0+ whitespace characters and end of string
[\s\S]+ Match 1+ times any character including new lines
$ End of string

edited Jan 08 '19 at 08:14

answered Jan 08 '19 at 08:02

The fourth bird

score 0 · Accepted Answer · answered Jan 08 '19 at 08:02

0

You can use the following regex:

^(?: *[^\s] *)+$

answered Jan 08 '19 at 08:02

Allan

2 Answers2