Regex for splitting word / (slash) word

Question

I really need a regex expert: I need a regex expression (in java) for splitting this examples:

Hello/World (word/word) => Hello,World

Hello/12 (word/number) => Hello,12

15/Hello (number/word) => 15,Hello

12/17 (number/number) => 12/17 (Do not split)

Update:

This is what I tried but it also mark the number/number option https://regex101.com/r/zZ9nO5/2

Thanks

So you don't want to split on `/` if it has digit before and after it. You can use https://www.regular-expressions.info/lookaround.html mechanism here. — Pshemo, Nov 14 '18 at 09:48
In addition to Pshemo's comment: could there be any whitespace before or after the slash, e.g. `12 / 17`? If so, should that change how you'd split? If not, then you'd need to add that to your regex. Try something with (negative) lookaround and if needed whitespace matching (`\s`) and if you have problems with that show us what you've tried. — Thomas, Nov 14 '18 at 09:52
there is no spaces after and before. I am really weak at regex, if someone know the exact expression to try it will be amazing. — UnknownUser, Nov 14 '18 at 10:07

Veselin Davidov · Accepted Answer · 2018-11-14T12:03:35.210

0

It might not be the most elegant solution but for your requirement you can do it like that:

(([a-zA-Z]+?)/([a-zA-Z]+))|(([a-zA-Z]+?)/([\d]+))|(([\d]+?)/([a-zA-Z]+))

It's a check for word / word, word / number and number / word

replace with the corresponding groups found \2\5\8,\3\6\9

A simple java program for that would be:

  public static void main(String[] args) {
            String[] stringArray=new String[]{"Hello/World","Hello/12","15/Hello","12/17"}; 
            for(String s:stringArray) {
                System.out.println(s.replaceAll("(([a-zA-Z]+?)/([a-zA-Z]+))|(([a-zA-Z]+?)/([\\d]+))|(([\\d]+?)/([a-zA-Z]+))", "$2$5$8,$3$6$9"));
            }
        }

Result is:

Hello,World
Hello,12
15,Hello
12/17

edited Nov 14 '18 at 12:03

answered Nov 14 '18 at 10:14

Veselin Davidov

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Can this be done without the groups? I mean that regex will mark the '/' – UnknownUser Nov 14 '18 at 11:11
Well it will mark the '/' but if you want to see what's on the two side of the slash then you need to match against that also. And in order to use that later on it will require a group. – Veselin Davidov Nov 14 '18 at 12:03
I don't need to look at it. It will split it anyway in my code – UnknownUser Nov 14 '18 at 12:13
You need the regex to look at it ;) in order to see if it is word/number or whatever. If you don't need to look at it just split on "/" – Veselin Davidov Nov 14 '18 at 12:21

Benjamin Basmaci · Answer 2 · 2018-11-14T10:45:21.673

A little more context would be nice but as I understand it, you get a string with a single '/' in the middle and you either replace the '/' with ',' or you dont if it has numbers on both sides. So i would do something like this:

public class MyClass {
 public static void main(String args[]) {
        String mystring = "12/25";

        if(!mystring.matches("^\\d+\\/\\d+$"))
            mystring = mystring.replace("/", ",");

        System.out.println(mystring);
    }
}

If that is what you wanted to do here, then I belive its less complicated and also quicker than a big regex destinguishing between all 4 cases.

score 0 · Answer 3 · edited Jun 20 '20 at 09:12

0

Slightly different approach, but you could check the characters in the String to see that they all are either a number or a forward slash, and then split if necessary:

   public static void main(String[] args) {
    String[] strArray = new String[]{"Hello/World", "Hello/12", "15/Hello", "12/17"};

    for(String str: strArray){
        if(checkIfValid(str)){
            System.out.println(str);
        }
        else{
            System.out.println(str.replace("/", ","));
        }
    }
}

public static boolean checkIfValid(String str) {
    for (int i = 0; i < str.length(); i++) {
        if (!Character.isDigit(str.charAt(i)) && str.charAt(i) != '/') {
            return false;
        }
    }
    return true;
}

Output:

Hello,World

Hello,12

15,Hello

12/17

This might help if Hello12/15 is not supposed to be split.

edited Jun 20 '20 at 09:12

Community

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answered Nov 14 '18 at 10:32

achAmháin

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there is no WordNumber in the language – UnknownUser Nov 14 '18 at 11:12
@UnknownUser that's fine - it will still work anyway. – achAmháin Nov 14 '18 at 11:35
I prefer regex solution since I already using it to split other expressions – UnknownUser Nov 14 '18 at 11:49

Regex for splitting word / (slash) word

3 Answers3