Regex failing for lower case, upper case, numbers and min 8 characters

Question

I've looked and found so much information for regex. It's super well documented, but I'm clearly being an idiot, or have looked at this issue for too long!

The pattern I need to match is any number of upper case, lower case and numbers, with at least 8 characters. I don't want to accept anything else, such as non-alphanumeric characters (_ *^& etc)

My effort is

^(?=.*[A-Z])(?=.*[a-z])(?=.*[0-9])\S{8,}$

Sadly, when I use https://regex101.com/ this does not match any of the following

aaaaaaaa
AAAAAAAA
00000000
asdfFDSA167
#fFaf9374A
12345678
123456NBh

2 of those are valid but I don't see why I'm having issues

The end goal is to use this in the pattern attribute for input (HTML 5 input pattern="" />`)

Replace `\S` (any non-whitespace char) with `[A-Za-z0-9]`. See https://regex101.com/r/k3ZzvK/1 — Wiktor Stribiżew, Mar 15 '19 at 18:53
Like `^(?=.*[A-Z])(?=.*[a-z])(?=.*[0-9])\[A-Za-z0-9]{8,}$ ` ? Still no difference — MyDaftQuestions, Mar 15 '19 at 18:56
Why did you escape the `[`? You ruined the character class. `^(?=.*[A-Z])(?=.*[a-z])(?=.*[0-9])[a-zA-Z0-9]{8,}$`, as in https://regex101.com/r/k3ZzvK/1 — Wiktor Stribiżew, Mar 15 '19 at 18:58
should it match `asdfFDSA167`? post says `2 of those are valid`. which 2? — Matt.G, Mar 15 '19 at 19:08
I was told look ahead was not ideal for javascript. If this is right, why is this a dupe — MyDaftQuestions, Mar 15 '19 at 19:23
Your answer is [here](https://stackoverflow.com/a/21456918/3832970). — Wiktor Stribiżew, Mar 15 '19 at 19:32

Jonathan Gray · Answer 1 · 2019-03-15T19:07:13.020

1

I believe this is what you're looking for: ^[a-zA-Z0-9]{8,}$

Or maybe this: ^[a-z]{8,}|[A-Z]{8,}|[0-9]{8,}$

The first one will match any combination of letters/numbers and the second one will only match sequences of like-characters. It's hard to tell exactly what you're looking for given the question.

EDIT: I made a mistake but fixed it

edited Mar 15 '19 at 19:07

answered Mar 15 '19 at 19:01

Jonathan Gray

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score 0 · Answer 2 · answered Mar 15 '19 at 19:04

0

Try this :

^(?=.*[A-Z])(?=.*[a-z])(?=.*[\d])([A-Za-z\d]{8,})$

DEMO

answered Mar 15 '19 at 19:04

Mohammed Elhag

4,272
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Regex failing for lower case, upper case, numbers and min 8 characters

2 Answers2