Matching consecutive characters with password limitation

Question

Hello guys I'm trying to match the following regex:

• Minimum characters: 8
• Maximum characters: 22
• Minimum uppercase letters: 1
• Minimum lowercase letters: 1
• Minimum digits: 2
• Special characters are allowed
• First character must be a letter
• Maximum consecutive identical characters: 2

I've manage to complete every condition but the consecutive ones with:

(?=^.{8,22}$)(?=(.*\d){2})(?=(.*[A-Z]))^[a-zA-Z].*$

Following the post RegEx No more than 2 identical consecutive characters and a-Z and 0-9 I've seen that the way of not matching exact characters is:

((.)\2?(?!\2))+

But I'm unable to mix them both and have the full matching result. The tries are being done here: https://regex101.com/r/94KaXO/1/ where the first string should match but not the second one.

Thanks in advance.

Answer 1

You can use

^(?=.{8,22}$)(?!.*(.)\1{2})(?=(?:\D*\d){2})(?=[^A-Z]*[A-Z])(?=[^a-z]*[a-z])[a-zA-Z].*$

See the regex demo.

Details:

• ^ - start of string
• (?=.{8,22}$) - 8 to 22 chars other than line break chars are allowed in the string
• (?!.*(.)\1{2}) - no 3 consecutive identical chars allowed anywhere after zero or more chars other than line break chars as many as possible
• (?=(?:\D*\d){2}) - there must be at least 2 not necessarily consecutive digits in the string
• (?=[^A-Z]*[A-Z]) - there must be at least one uppercase letter in the string
• (?=[^a-z]*[a-z]) - there must be at least 2 one lowercase letter in the string
• [a-zA-Z] - a letter
• .* - zero or more chars other than line break chars, as many as possible
• $- end of string.