CODEWITHSUNDEEP
javaregex
srv
srv

Reputation: 440

Regex single character user name validation

Regular expression mentioned below is used to validate a user input in Java.

username.matches("^\\p{L}+[\\p{L}\\p{Z}.']+")

The regular expression is working for more than one character input, but fails for single character input.

As '+' denotes one and more than one characters, I confused how to support one character input as valid input.

Upvotes: 0

Views: 152

Answers (3)

Dmitry Pisklov
Dmitry Pisklov

Reputation: 1206

The regex you have will match 2 or more symbols. The reason is, this is symbol one (or more):

\\p{L}+

And this is symbol 2 (or more):

[\\p{L}\\p{Z}.']+

Most likely you want the last part to be "0 or more", like this:

"^\\p{L}+[\\p{L}\\p{Z}.']*"

Upvotes: 1

DwB
DwB

Reputation: 38338

Your regex requires a minimum of 2 characters.

"^\p{L}+" - minimum of 1
"[\p{L}\p{Z}.']+" - minimum of 1

The "+" does denote one or more characters.

Upvotes: 1

mjuarez
mjuarez

Reputation: 16854

That's because both parts in your regex are requiring at least one character each (see the + almost at the end of the regex). If you want that part to be optional, it should be * instead.

Upvotes: 2

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