regex to get word between two undescores

问题

I've a line like bla_bla**_**test**_1**023

and would like to extract the word between _ and any underscore followed by digit _digit which is test in the above example.

I've tried the following regex but unfortunately does not work: [^_ ]+(?=[ _\d]) - it getting me all words before "_digit" not only the one which is before _digit

回答1:

This should work for you. Use Pattern and Matcher with look-arounds.

public static void main(String[] args) {
    String word= "bla_bla_test_1023";
    Pattern p = Pattern.compile("(?<=_)([^_]+)(?=_\\d+)");
    Matcher m = p.matcher(word);
    while (m.find()) {
        System.out.println(m.group());
    }


}

O/P :

test

回答2:

 [^_]*(?=_\d)

You want to match everything other than _ until you get to _ followed by a digit.

来源：https://stackoverflow.com/questions/53013824/regex-to-get-word-between-two-undescores