What is the regex to make sure that a given string contains at least one character from each of the following categories.
I know the patterns for individual sets namely [a-z], [A-Z], \d and _|[^\w] (I got them correct, didn't I?).
But how do I combine them to make sure that the string contains all of these in any order?
If you need one single regex, try:
(?=.*\d)(?=.*[a-z])(?=.*[A-Z])(?=.*\W) A short explanation:
(?=.*[a-z]) // use positive look ahead to see if at least one lower case letter exists (?=.*[A-Z]) // use positive look ahead to see if at least one upper case letter exists (?=.*\d) // use positive look ahead to see if at least one digit exists (?=.*\W) // use positive look ahead to see if at least one non-word character exists And I agree with SilentGhost, \W might be a bit broad. I'd replace it with a character set like this: [-+_!@#$%^&*.,?] (feel free to add more of course!)
.+ into .*? I couldn't come up with a test case that fails with .*. Are they same in this context? "Zero or more characters" seems to be fine - just seeking confirmation.
.+ into .* or even .{4,} for that matter.
(?=.*[_\W]) doesn't work regex101.com/r/jH9rK1/1^(?=.*[a-z])(?=.*[A-Z])(?=.*\d)(?!.*[&%$]).{6,}$Bart Kiers, your regex has a couple issues. The best way to do that is this:
(.*[a-z].*) // For lower cases (.*[A-Z].*) // For upper cases (.*\d.*) // For digits (.*\W.*) // For symbols (non-word characters) In this way you are searching no matter if at the beginning, at the end or at the middle. In your have I have a lot of troubles with complex passwords.
Bart Kiers solution is good but it misses rejecting strings having spaces and accepting strings having underscore (_) as a symbol.
Improving on the Bart Kiers solution, here's the regex:
(?=.*\d)(?=.*[a-z])(?=.*[A-Z])((?=.*\W)|(?=.*_))^[^ ]+$
A short explanation:
(?=.*[a-z]) // use positive look ahead to see if at least one lower case letter exists (?=.*[A-Z]) // use positive look ahead to see if at least one upper case letter exists (?=.*\d) // use positive look ahead to see if at least one digit exists (?=.*\W) // use positive look ahead to see if at least one non-word character exists (?=.*_) // use positive look ahead to see if at least one underscore exists | // The Logical OR operator ^[^ ]+$ // Reject the strings having spaces in them. Side note: You can try test cases on a regex expression here.
^[^ ]+$You can match those three groups separately, and make sure that they all present. Also, [^\w] seems a bit too broad, but if that's what you want you might want to replace it with \W.
\W and [\W] result in the same.