What is the regular expression for this "password"?

Question

I want regular expression that contains at least one alphanumeric character, at least one non alphanumeric character (special character) and at least one digit.

Thanks in advance.

Answer 1

Correct answer of my question :

regular Expression :

^((?=.[\d])(?=.[a-z])(?=.[A-Z])|(?=.[a-z])(?=.[A-Z])(?=.[^\w\d\s])|(?=.[\d])(?=.[A-Z])(?=.[^\w\d\s])|(?=.[\d])(?=.[a-z])(?=.[^\w\d\s])).{8,30}$

Thanks.

Answer 2

So, in other words, at least one alpha, one digit, and one non-alphanum...

You need two lookaheads:

(?=.*[a-zA-Z])(?=.*[0-9]).*[^a-zA-Z0-9]

Since this is marked as homework, I suggest you actually understand it, too:

http://www.regular-expressions.info/lookaround.html

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In case you don't want spaces either:

(?=.*[a-zA-Z])(?=.*[0-9]).*(?=\S)[^a-zA-Z0-9]

Answer 3

Since this is homework (or perhaps not?), here is a hint for a solution that doesn't use look-aheads or other nifty tricks.

In how many (and it what) permutations can the characters occur? How can this be used with the alternation (|) operator?

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I would use multiple tests and not a single regex :-)

Happy coding.

Answer 4

It would be easy to pick out any one of them, but to have all three of them in any order would be something. You could try a single character of one of the three then use look aheads for the remaining, but you would still need to check behind that character too.