Regex for upper and lower+numbers or other non-alphabetic

See my post here

Regex for at least 8 + upper and lower+numbers or other non-alphabetic

Suppose i just need this 2 condition below, what should be the regular expression?

1. Contains upper and lower 开发者_StackOverflowcase letters.
2. Contains numbers or other non-alphabetic characters.

I tried ^(?=.*?[a-z])(?=.*?[A-Z])(?=.*?[^a-zA-Z])$ but not working

BUT just- -(?=.*?[a-z])(?=.*?[A-Z])(?=.*?[^a-zA-Z]) is working

can i use just (?=.*?[a-z])(?=.*?[A-Z])(?=.*?[^a-zA-Z]) for the purpose?

The problem here is that the look ahead/behind are zero-width, "non-consuming". That means your

^(?=.*?[a-z])(?=.*?[A-Z])(?=.*?[^a-zA-Z])$

will never match because the lookarounds consumed nothing and whats then left? only ^$ that would match an empty string, but this does not meet your lookahead criterias.

So you should use

^(?=.*?[a-z])(?=.*?[A-Z])(?=.*?[^a-zA-Z]).*$

that .* will consume everything and the look aheads ensure the criterias.

you can also define a length replacing the * with {x,} where x is the minimum amount of characters of the string

^(?=.*?[a-z])(?=.*?[A-Z])(?=.*?[^a-zA-Z])$

this means: start of string followed by anything containing lowercase or uppercase or non-alphabetic, but the next position must be end of string - this can not happen.

Your accepted aswer in your previous question is OK, is there any problem? Here you can read something more about assertions in regex http://cz.php.net/manual/en/regexp.reference.assertions.php