Question

I would like a regular expression for removing all special characters except an underscore. I can replace all special characters, but I don’t know how to keep the underscores. Here’s the code for removing all speial characters,

String myname= "!john_smith@#-".replaceAll("\\p{Punct}+", "");

Any ideas how to modify the regex so that I keep underscores?

Thanks,
Patrick

Answer 1

Well \\p... is the same as [^\\P...] (negated character class of characters not having the property), and then you could put the underscore in there as well:

"[^\\P{Punct}_]+"

Alternatively, use a negative lookahead

"(?:(?!_)\\p{Punct})+"

Also, seeing your example, maybe something as simple as this will be enough for you:

"[^\\w\\s]+"

Will remove everything except for letters, digits, underscores and whitespace.