REGEX az 0-9但不仅仅是数字

Question

Trying to match only strings 10-30 characters long with only az and 0-9 (but not only numbers) in the string. Seems to work Except when the string starts with a number then it fails. Not sure about the \\D which should fix the not only numbers

static final Pattern UNIQUE_ID_PATTERN = Pattern.compile("^\\D[A-Za-z0-9_-]{10,30}$");
UNIQUE_ID_PATTERN.matcher("1eeeeeeeee333e").matches(); // Does not work
UNIQUE_ID_PATTERN.matcher("eeeeeeeee333e").matches(); // Works

Answer 1

The \\D shorthand class means any non-digit symbol . You should remove it from the pattern (so that it becomes "^[A-Za-z0-9_-]{10,30}$" ) for the matches to return true, as 1 is a digit in 1eeeeeeeee333e .

If you want to place a restriction (the string cannot consist of only digits) use an anchored look-ahead:

^(?![0-9]+$)[A-Za-z0-9_-]{10,30}$

Here is a demo

Or, a shortened version with i modifier making the pattern case-insensitive:

(?i)^(?![0-9]+$)[A-Z0-9_-]{10,30}$

Answer 2

Another way: ^(?=(?:.*[a-zA-Z])+)([a-zA-Z\\d]{10,30})$ update

Demo

More details