Take a string as input and if it meets the requirements, accept the password.

Input: a string, e.g. someString, asjk23t89h, 123456789abcdef.

Output: two distinct values representing "secure" and "insecure", e.g. 0/1, true/false, secure/insecure.

Password requirements:

In order for a password to be determined as secure, it must:

  • Be at least 8 characters in length.
  • Contain at least one character each from the four groups a-z, A-Z, 0-9 and !"£$%^&*()_+-={}[]:@~;'#<>?,./


  • password -> insecure
  • password123 -> insecure
  • L0h~[/1s7C -> secure
  • h&fn3*# -> insecure
  • C#de g07F -> secure


This is code golf, the shortest answer wins.

  • 3
    \$\begingroup\$ Related. \$\endgroup\$ – Laikoni Oct 16 '17 at 10:52
  • \$\begingroup\$ Can you clarify the "ASCII symbol" part? Do you mean any non-letter, non-digit ASCII character (including spaces, linefeeds, and other control characters)? Or do you mean printable/non-whitespace ASCII only? Also what range of characters can appear in the input in the first place? \$\endgroup\$ – Martin Ender Oct 16 '17 at 12:34
  • 2
    \$\begingroup\$ Did you add a non-ASCII character (£) to the list intentionally? \$\endgroup\$ – Martin Ender Oct 16 '17 at 12:39
  • \$\begingroup\$ "Is my password secure?" s->"no" (7 bytes answer in Java \o/) \$\endgroup\$ – Olivier Grégoire Oct 16 '17 at 14:36

Java 8, 93 62 65 60 bytes


+3 bytes due to a bugfix, pointed out by @MartinEnder♦.
-5 bytes thanks to @jaytea by using capture groups instead of lookaheads, since the matches are not overlapping.

Old answer with (redundant) dictionary (93 96 bytes):


Because I can't think of a single word in the dictionary that contains at least one uppercase, lowercase, digit and other ASCII character.. So the dictionary-check is kinda redundant in that case.


Try it here.

s->                    // Method with String parameter and boolean return-type
  s.matches("([a-z]()  //  Checks if the String contains at least one lowercase letter
             |[A-Z]()  //  and at least one uppercase letter
             |\\d()    //  and at least one digit
             .()       //  and at least one other ASCII character
                       //  And has a length of at least 8
                       // End of method (implicit / single-line return-statement)
  • 1
    \$\begingroup\$ Here is a trick for golfing multiple, non-overlapping subexpressions that's shorter than using lookaheads: "([a-z]()|[A-Z]()|\d()|.()){8,}+\2\3\4\5" \$\endgroup\$ – jaytea Oct 16 '17 at 14:30

Python 2, 112 107 83 86 bytes

lambda s:re.match(r'(?=.*[a-z])(?=.*[A-Z])(?=.*\d)(?=.*[\W_]).{8,}',s)!=None
import re

Try it online!

  • 2
    \$\begingroup\$ You can remove the !=None as the match will either return a truthy or falsey value (a match object or None) \$\endgroup\$ – caird coinheringaahing Oct 16 '17 at 15:18

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