Regular expression for a password

Question

A regular expression for password

It should have one number
One character compulsorily
Not case sensitive.
Special character is not mandatory.

xyz.match(/^(?:[0-9]+[a-z]|[a-z]+[0-9])[a-z0-9]*$/i)

In this if we give special character it is not accepting

asd12   //working
Asd123  //working
Asd123@ //not working

Wiktor Stribiżew · Accepted Answer · 2015-09-11T09:46:35.947

1

You need 2 look-aheads anchored at the beginning instead of a non-capturing group:

/^(?=[^0-9]*[0-9])(?=[^a-z]*[a-z]).*$/i
  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

The .* subpattern will allow any characters, but the look-aheads will demand at least 1 digit and 1 Latin letter.

Note that non-capturing groups still consume characters, and cannot be used to check for presence or absence of specific subpatterns in a string. Only zero-width assertions provide that mechanism.

See this regex demo

edited Sep 11 '15 at 09:46

answered Sep 11 '15 at 09:42

Wiktor Stribiżew

607,720
39
448
563

its working thank you :) – mage-kat Sep 11 '15 at 09:45
FYI: if you want to match `xyz1` and `123xyz`, but not match `123xyz@`, use `/^(?=[^0-9]*[0-9])(?=[^a-z]*[a-z])[a-z0-9]*$/i` (the same `[a-z0-9]*` as in your original regex). – Wiktor Stribiżew Sep 11 '15 at 09:49
Could you please update the programming language tag? Is it JavaScript? – Wiktor Stribiżew Sep 11 '15 at 09:52
thank you its prototype. Accepted the answer :) – mage-kat Sep 11 '15 at 10:34

Regular expression for a password

1 Answers1