How to match a string's end using a regex pattern in Java?

Question

I want a regular expression pattern that will match with the end of a string.

I'm implementing a stemming algorithm that will remove suffixes of a word.

E.g. for a word 'Developers' it should match 's'.
I can do it using following code :

Pattern  p = Pattern.compile("s");
Matcher m = p.matcher("Developers");
m.replaceAll(" "); // it will replace all 's' with ' '

I want a regular expression that will match only a string's end something like replaceLast().

Answer 1

You need to match "s", but only if it is the last character in a word. This is achieved with the boundary assertion $:

input.replaceAll("s$", " ");

If you enhance the regular expression, you can replace multiple suffixes with one call to replaceAll:

input.replaceAll("(ed|s)$", " ");