Regex with numbers and alphabets mandatory, special characters optional

Question

In my application edittext value need at least one digit and one alphabet is mandatory, and some special characters are optional i.e ".-", like any whare in the string. For example ram123-. or r_m-12.m or .--ram123 or ram123.-_. For this I need regex. I have already tried with this one

str_userId.matches("[A-Za-z0-9]*+[?.?_?-]")

But not working. Here how to add special characters are optional.

Thanks, In Advance

Try `^(?=[^a-z\n]*[a-z])[A-Za-z._-]*[0-9][A-Za-z0-9._-]*$` See https://regex101.com/r/RQZT7g/1 — The fourth bird, Jul 09 '20 at 08:01
Probably a dupe of [Regex pattern to match at least 1 number and 1 character in a string](https://stackoverflow.com/questions/7684815/regex-pattern-to-match-at-least-1-number-and-1-character-in-a-string) — Wiktor Stribiżew, Jul 09 '20 at 08:20

score 2 · Answer 1 · answered Jul 09 '20 at 08:20

You could use a positive lookahead (?= to assert at least one occurrence of a-z and after that match at least a single digit [0-9].

Before and after matching the digit, you could add the . _ and - to the character class [A-Za-z._-]* and repeat it 0+ times.

Note that a character class matches on of the listed characters. This notation [?.?_?-], which could be written as [?._-] would also match a question mark instead of making the others optional

^(?=[^a-z\n]*[a-z])[A-Za-z._-]*[0-9][A-Za-z0-9._-]*$

Regex demo

Regex with numbers and alphabets mandatory, special characters optional

1 Answers1