Java regular expression to remove all non alphanumeric characters EXCEPT spaces

Question

I\'m trying to write a regular expression in Java which removes all non-alphanumeric characters from a paragraph, except the spaces between the words.

This is the co

Answer 1

You need to double-escape the \ character: "[^a-zA-Z0-9\\s]"

Java will interpret \s as a Java String escape character, which is indeed an invalid Java escape. By writing \\, you escape the \ character, essentially sending a single \ character to the regex. This \ then becomes part of the regex escape character \s.