Regex to split Camel case - with Numbers

Question

I want to split a camelCase name to individual names using regex, for performing a spell check.

The split should be as follows:

1) extendedStructureForNUB --> extended, Structure, For, NUB

2) extendedStructureFor2004 --> extended, Structure, For, 2004

Using the answer from the below question , i am able to split for the 1st condition.

Question : RegEx to split camelCase or TitleCase (advanced)

But for a string containing number (2nd condition), it is not returning as per format.

extendedStrctureFor2004 --> extended, Structure, For2004

Please suggest a way by which i can reuse this regex to split numerals also.

Hello2000WORLD --> Hello,2000, WORLD – Unni Kris May 31 '12 at 09:03 — Unni Kris, May 31 '12 at 09:03
MYNewString --> MY New String – Unni Kris May 31 '12 at 09:16 — Unni Kris, May 31 '12 at 09:16

Daren Schwenke · Accepted Answer · 2012-05-31T10:22:16.243

4

public static void main(String[] args) 
{     
    for (String w : "camelValue".split("(?<!(^|[A-Z0-9]))(?=[A-Z0-9])|(?<!^)(?=[A-Z][a-z])")) {
         System.out.println(w);
    } 
}

Edit: Correcting the case for UPPER2000UPPER the regex becomes:

public static void main(String[] args) 
{     
    for (String w : "camelValue".split("(?<!(^|[A-Z0-9]))(?=[A-Z0-9])|(?<!(^|[^A-Z]))(?=[0-9])|(?<!(^|[^0-9]))(?=[A-Za-z])|(?<!^)(?=[A-Z][a-z])")) {
         System.out.println(w);
    } 
}

edited May 31 '12 at 10:22

answered May 31 '12 at 08:53

Daren Schwenke

5,428
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Typo mistake. Checked and Working !! Thanks. Deleted my comment. – Unni Kris May 31 '12 at 09:21
Fixed. That's a lot of backtracking though. – Daren Schwenke May 31 '12 at 10:36
Great Work. Perfect. Works in all conditions. "123IsJust345CheckNO678GOOD90" --> [123, Is, Just, 345, Check, NO, 678, GOOD, 90] – Unni Kris May 31 '12 at 10:36
@DarenSchwenke Also can you please tell whether this much backtracking will affect performance? – Unni Kris May 31 '12 at 10:37
Given your input string is words, and you are only going back up to a word at a time, probably not. Benchmark if paranoid or just worry about it if it's too slow later. <- me. – Daren Schwenke May 31 '12 at 10:47

Vitaly Dyatlov · Answer 2 · 2012-05-31T08:57:09.340

1

public static void main(String[] args)
{
    for (String w : "extended2004FeeStructure".split("(?<!(^|[A-Z0-9]))(?=[A-Z0-9])|(?<!^)(?=[A-Z][a-z])")) {
        System.out.println(w);
    }
}

corrected one

edited May 31 '12 at 08:57

answered May 31 '12 at 08:49

Vitaly Dyatlov

1,872
14
24

This will return [extended, 2, 0, 04, Fee, Structure] for extended2004FeeStructure. What i need is [extended, 2004, Fee, Structure] – Unni Kris May 31 '12 at 08:52
Checked and Working !! Thanks. +1 – Unni Kris May 31 '12 at 09:19

Pshemo · Answer 3 · 2012-05-31T09:38:09.633

What I see is answer from your previous question was almost pervect. If I ware you i would just add another split opperation, but this time before first digit in middle in each word.

Here is example:

String data="2Hello2000WORLDHello2000WORLD";
//your previois split
String[] myFirstSplit=data.split("(?<!(^|[A-Z]))(?=[A-Z])|(?<!^)(?=[A-Z][a-z])");

//I will store split results in list (I don't know size of array)
List<String> list=new ArrayList<>();
for (String s:myFirstSplit){
    //if splited word contains digit after letter then split
    for (String tmp:s.split("(?<=[a-zA-Z])(?=[0-9])"))
        list.add(tmp);
}
System.out.println(list);
//out [2, Hello, 2000, WORLD, Hello, 2000, WORLD]

This will work for in my case, but i am not sure how much performance efficient it will be. I need to compare all the variable names in a code base (which may easily contain thousands or lakhs of variable names) against a spell check dictionary. — Unni Kris, May 31 '12 at 10:04

score 0 · Answer 4 · answered May 31 '12 at 08:53

0

After you seperate this

extendedStrctureFor2004 --> extended, Structure, For2004

Store it in some array like "arr"

Use this Regex

var numberPattern = /[0-9]+/g; var numMatch= arr[i].match(numberPattern);

now numMatch will contain the numerals u want..

answered May 31 '12 at 08:53

Kabilan S

1,104
4
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This is about Java, not JavaScript. – Maarten Bodewes Jun 03 '17 at 14:28

Regex to split Camel case - with Numbers

4 Answers4