Regular Expression Explanation [\w-\.]

Question

What does this RegExp mean please?

[\w-\.]

I know the \w stands for word characters and could alternatively be written as:

[A-Za-z0-9_]

I know the \. means that the point will be treated as an ordinary character.

The only thing I don't really know is the hyphen character. Is this used as a Range Operator here or just the hyphen character in e.g. "fine-tune"?

FYI there's no need to escape the dot `.` in a character class, `[\w-.]` will work just fine. — Robin, Jul 01 '14 at 07:36

score 1 · Accepted Answer · answered Jul 01 '14 at 06:44

1

Hyphen here is just the hyphen character.

Hyphen is treated as a range operator only when it is between two other characters.

answered Jul 01 '14 at 06:44

xdazz

score 0 · Answer 2 · answered Jul 01 '14 at 06:40

0

Hyphen is normal character here, so it works as [a-zA-z0-9_-\.] (number, letters, and these three characters: -_.).

answered Jul 01 '14 at 06:40

pavel

Be careful, in `[a-zA-z0-9_-.]` the `-` *would* be interpreted as a range - and cause an error since `_` ascii value is greater than `.`. I'm guessing you meant `[a-zA-z0-9_.-]` ? – Robin Jul 01 '14 at 07:43

2 Answers2