Match decimals from a string with regex

Question

I want to get two decimals from a string using a Regex but I get only the first.

getGroupCount is correct but I get always {1} and I don't know why. I'm using GWT 2.5. Here is my code:

private void readOffset(){
    RegExp regExp = RegExp.compile("(\\{\\d\\})");

    MatchResult matcher = regExp.exec("(cast({1} as float)/{24})");

    String val1 = matcher.getGroup(0);
    String val2 = matcher.getGroup(1);
}

Why might this be happening?

You are using package RegExp and MatchResult from com.google.gwt.regexp.shared package on gwt client side code? — appbootup, Jan 09 '13 at 10:58
If you are expecting gwt client side code help then you should remove regex/java tag. GWT Regex is different!!!!! — appbootup, Jan 09 '13 at 11:19

npinti · Answer 1 · 2013-01-09T10:58:32.527

1

The operator \d will only yield 1 digit. If you want to get two, you would need to use \d{2}. If you need to match more, you would need to use \d+, where + means 1 or more repetitions of.

Something like so worked for me (Java though, not exactly GWT):

        String str = "(cast({1} as float)/{24})";
        Pattern p = Pattern.compile("(\\{\\d+\\})");
        Matcher m = p.matcher(str);         
        while(m.find())
        {
            System.out.println(m.group(1));
        }

Yields: {1} and {24}

edited Jan 09 '13 at 10:58

answered Jan 09 '13 at 10:46

npinti

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Apart from that, he's confusing groups with matches – John Dvorak Jan 09 '13 at 10:51
i changed to \d+ but i get still the same group. – user1573659 Jan 09 '13 at 10:54
@user1573659 I have added some extra Java code which should guide you in the right direction. – npinti Jan 09 '13 at 10:59
GWT Regex implementation is different from normal regex. Normal java answers probably may not work – Abhijith Nagaraja Jan 09 '13 at 12:16

score 0 · Answer 2 · answered Jan 09 '13 at 11:20

0

To learn how to use Regex in GWT client side please go through the Unit test cases in GWT for Regex. Reference - GWT Unit Test for Regex

Also you should be using RegExp and MatchResult from com.google.gwt.regexp.shared.

answered Jan 09 '13 at 11:20

appbootup

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Can you just not replicate this in GWT - http://stackoverflow.com/questions/1623221/how-to-find-a-number-in-a-string-using-javascript – appbootup Jan 09 '13 at 15:06

score 0 · Answer 3 · answered Jan 10 '13 at 07:53

im to stupid for the regex so i solved it quick and dirty:

private void readOffset(){
    String offset = manager.get("offset");

    String v1 = offset.substring(offset.indexOf("{")+1, offset.indexOf("}"));
    String v2 = offset.substring(offset.lastIndexOf("{")+1, offset.lastIndexOf("}"));

    multiplikator.setValue(v1);
    divisor.setValue(v2);

    /*
    RegExp regExp = RegExp.compile(".*({\\d+}).*", "g");
    MatchResult matcher = regExp.exec(offset);
    boolean matchFound = (matcher != null);

    if(matchFound == true && matcher.getGroupCount() == 2){
        String val1 = matcher.getGroup(0);
        String val2 = matcher.getGroup(1);

        multiplikator.setValue(matcher.getGroup(0));
        divisor.setValue(matcher.getGroup(1));
    }else{
        multiplikator.setValue("1");
        divisor.setValue("1");
    }
    */
}

better solutions are welcome :(

Match decimals from a string with regex

3 Answers3