Issue with Java Regex \b

Question

I tried \\b (This means the last character of a word) in the Java Regexp, but this doesn\'t work.

String input = \"aaa aaa\";
Pattern pattern =          


        

Answer 1

In Java, "\b" is a back-space character (char 0x08), which when used in a regex will match a back-space literal.

You want the regex a\b, which in java is coded by escaping the back-slash, like this:

"a\\b"

btw, you are only partially correct about the meaning of regex \b - it actually means "word boundary" (either the start or end of a word).

Answer 2

Literal backslashes in Java strings need escaping, so the regex \b becomes "\\b" as a Java string.