regex - Non-greedy Regular Expression in Java

Question

I have next code:

public static void createTokens(){
    String test = "test is a word word word word big small";
    Matcher mtch = Pattern.compile("test is a (\s*.+?\s*) word (\s*.+?\s*)").matcher(test);
    while (mtch.find()){
        for (int i = 1; i <= mtch.groupCount(); i++){
            System.out.println(mtch.group(i));
        }
    }
}

And have next output:

word
w

But in my opinion it must be:

word
word

Somebody please explain me why so?

Answer 1

Because your patterns are non-greedy, so they matched as little text as possible while still consisting of a match.

Remove the ? in the second group, and you'll get
word
word word big small

Matcher mtch = Pattern.compile("test is a (\s*.+?\s*) word (\s*.+\s*)").matcher(test);