Constructing a specific regex

Question

I want to make a regular expression in Java, with the next criteria:

• Length: 10 characters exactly. Not more, not less.
• Can accept any character between A-Z (only uppercase letters) and between digits 0-9.
• Can accept only one dash character '-' in any position. It cannot accept any other characters, strictly only one dash.

EXAMPLES:

• ABCD-12345
• F-01234GHK
• 09-PL89GG5
• LJ8U9N3-Y2
• PLN86D4V-1

I have been making tries with regex of my own invention, some regular expressions that are close to the result I want, but with no success.

Do I have to combine two regular expressions?

Please, help me to get rid of this issue.... and thanks in advance!!!

Answer 1

You can use this:

^(?![^-]*+-[^-]*+-)[A-Z0-9-]{10}$

Note: If you use the matches method you can remove anchors.

Answer 2

I think you need lookahead (which is a way of combining two regular expressions, sort of).

^(?!.*-.*-)[A-Z0-9-]{10}$

The second part will match 10 characters that are A-Z, 0-9, or dash; the first part is negative lookahead that will reject a pattern that has two dashes in it.