Split a String based on regex

Question

I have a string that needs to be split based on the occurrence of a ","(comma), but need to ignore any occurrence of it that comes within a pair of parentheses. For example, B2B,(A2C,AMM),(BNC,1NF),(106,A01),AAA,AX3 Should be split into

B2B,
(A2C,AMM),
(BNC,1NF),
(106,A01),
AAA,
AX3

Maybe you could check csv parsers. That's exactly what they do, except that they deal with quotes instead of parentheses. — Christophe, Oct 06 '12 at 04:34
What about the string "B2B,((A2C,AMM),CCC),(ABC,CBA),AAA"? Do you need to deal with something like this (ie, balanced parenthesis)? If so, forget about regexes, it is impossible (and I really mean *impossible*, not simply *extremely hard*). — Bruno Reis, Oct 06 '12 at 05:07

Anirudha · Accepted Answer · 2012-10-06T06:50:36.060

6

FOR NON NESTED

,(?![^\(]*\))

FOR NESTED(parenthesis inside parenthesis)

(?<!\([^\)]*),(?![^\(]*\))

edited Oct 06 '12 at 06:50

answered Oct 06 '12 at 04:26

Anirudha

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xdazz · Answer 2 · 2012-10-06T04:55:11.323

2

Try below:

var str = 'B2B,(A2C,AMM),(BNC,1NF),(106,A01),AAA,AX3';
console.log(str.match(/\([^)]*\)|[A-Z\d]+/g));
// gives you ["B2B", "(A2C,AMM)", "(BNC,1NF)", "(106,A01)", "AAA", "AX3"]

Java edition:

String str = "B2B,(A2C,AMM),(BNC,1NF),(106,A01),AAA,AX3";
Pattern p = Pattern.compile("\\([^)]*\\)|[A-Z\\d]+");
Matcher m = p.matcher(str);
List<String> matches = new ArrayList<String>();
while(m.find()){
    matches.add(m.group());
}

for (String val : matches) {
    System.out.println(val);
}

edited Oct 06 '12 at 04:55

answered Oct 06 '12 at 04:15

xdazz

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`'\([^)]*\)|[^,()]+'` is another alternative that would allow more characters besides capital letters and digits. – user650654 Oct 06 '12 at 04:23
@user650654 Yes, that's true. – xdazz Oct 06 '12 at 04:24
@Evgeni It's console not Console. – xdazz Oct 06 '12 at 04:28
Note using String.split(...) in Java will not give the desired results. – LanguagesNamedAfterCofee Oct 06 '12 at 04:31

Pshemo · Answer 3 · 2012-10-06T05:19:13.593

One simple iteration will be probably better option then any regex, especially if your data can have parentheses inside parentheses. For example:

String data="Some,(data,(that),needs),to (be, splited) by, comma";
StringBuilder buffer=new StringBuilder();
int parenthesesCounter=0;
for (char c:data.toCharArray()){
    if (c=='(') parenthesesCounter++;
    if (c==')') parenthesesCounter--;
    if (c==',' && parenthesesCounter==0){
        //lets do something with this token inside buffer
        System.out.println(buffer);
        //now we need to clear buffer  
        buffer.delete(0, buffer.length());
    }
    else 
        buffer.append(c);
}
//lets not forget about part after last comma
System.out.println(buffer);

output

Some
(data,(that),needs)
to (be, splited) by
 comma

score 0 · Answer 4 · edited Oct 06 '12 at 06:16

Try this

\w{3}(?=,)|(?<=,)\(\w{3},\w{3}\)(?=,)|(?<=,)\w{3}

Explanation: There are three parts separated by OR (|)

\w{3}(?=,) - matches the 3 any alphanumeric character (including underscore) and does the positive look ahead for comma
(?<=,)\(\w{3},\w{3}\)(?=,) - matches this pattern (ABC,E4R) and also does a positive lookahead and look behind for the comma
(?<=,)\w{3} - matches the 3 any alphanumeric character (including underscore) and does the positive look behind for comma

Split a String based on regex

4 Answers4

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