Find sequence in text with at least one digit AND one letter AND some other conditions with RegEx

Chr3is :

I have following RegEx: (([a-zA-Z0-9?]{4,8})(-[a-zA-Z0-9?]{4,8})+-([a-zA-Z0-9?]{4,8}))

How can I avoid matching sequences which do not contain at least one digit AND one character (a-zA-Z)?

For example:

This text: Hello World 123 abc 1AB2C-D3FGH-456I7-JK8LM-NOP9Q Hello World 123 abc should return 1AB2C-D3FGH-456I7-JK8LM-NOP9Q

and this: Hello World 123 abc 11111-1111-1111 Hello World 123 abc

or

Hello World 123 abc aaaa-aaaa-aaaa-aaa Hello World 123 abc

should return nothing.

I develop in Java and get the group like this:

public List<String> getKeys() {
    keys = new ArrayList<>();
    Matcher matcher = KEY_REGEX.matcher(text);
    while (matcher.find()) {
        keys.add(matcher.group());
    }
    return keys;
}

Thanks!

The fourth bird :

One way is to use a positive lookahead (?= to check for at least an occurrence of A-Z and a digit 0-9

To match the occurrences in the - in the lookahead to find both, you could add it to the character class.

When matching, you start matching chars A-Z0-9 and repeat a group prepending the - so that there are no consecutive occurrences of - and not at the start or at the end.

\b(?=[A-Z0-9-]*[A-Z])(?=[A-Z0-9-]*[0-9])[A-Z0-9]+(?:-[A-Z0-9]+)+\b

• \b Word boundary
• (?=[A-Z0-9-]*[A-Z]) Assert a char A-Z
• (?=[A-Z0-9-]*[0-9]) Assert a digit 0-9
• [A-Z0-9]+ Match 1+ occurrences of A-Z0-9
• (?:-[A-Z0-9]+)+ Repeat matching 1+ occurrences of A-Z0-9 with - prepended
• \b Word boundary

Regex demo

Note that [A-z] matches more than [A-Za-z]

---

Limiting the character class to 4-8 occurrences:

\b(?=[A-Z0-9-]*[A-Z])(?=[A-Z0-9-]*[0-9])[A-Z0-9]{4,8}(?:-[A-Z0-9]{4,8})+\b