Regex replace non-word except dash

Question

I have a regex pattern (\\W|_)[^-] doesn\'t work for h_e.l_l.o - w_o.r_d (replacement string is \" \").

It returns something like this:

Answer 1

To match any non-word char except dash (or hyphen) you may use

[^\w-]

However, this regular expression does not match _.

You need a negated character class that matches any char other than letters, digits and hyphens:

/[^-a-zA-Z0-9]+/

or (with a case insensitive modifier):

/[^-a-z0-9]+/i

See demo.

Note that the - is placed at the character class start, and does not require escaping.

You may add a plus at the end to match all the unwanted characters at a stretch to remove them in one go.

If you want to make your pattern Unicode aware (that is, in some regex flavors, if you use shorthand character classes with/without some flags, they will also match all Unicode counterparts), you may use

/[^\w-]|_/

See the regex demo (or /(?:[^\w-]|_)+/ to grab the whole chunk of these chars).

Here, [^\w-] matches any char that is not a word char (letter, digit, or underscore) and the second alternative _ matches underscores.