Split a String, deleting some delimiters but keeping others

Question

Ok, so my problem is that I want to be able to parse a string and split it, keeping some delimiters and deleting others.

Let's say my input string is 1.8.0a . I want to be able to put the string into an array, [1, 8, 0, a] . I've seen other SO questions , and the best answer is close to what I want. My current code is:

String[] array = s.split("[-._[?<=a[b[r]]]]");

The only problem is that my output is

[1, 8, 0]

EDIT:

Here's a few more examples:

Input: 1.18.0a

Output: [1, 18, 0]

Expected output: [1, 18, 0, a]

Input: 1.22.0r

Output: [1, 22, 0]

Expected output: [1, 22, 0, r]

Also, I used parenthesis,

String[] array = s.split("[-._(?<=a[b[r]])]");

Still to no avail.

Answer 1

If you just want to handle version strings like this, I personally would just walk through the string character by character, copying characters into a StringBuilder until I reached a delimiter, then convert the StringBuilder to a String and store it in the array. That would allow me to consider the switch from digits to letters as a "delimiter".

But then, I find regular expressions quite opaque. They're useful in some cases, but sometimes plain Java code, while more verbose, is simpler and easier to understand.

Answer 2

It looks like you want to split

• on - . _
• or between digit and alphabetic characters.

In that case you can try with

yourText.split("[-._]|(?<=[0-9])(?=[a-zA-Z])")

Answer 3

You can use the following regex:

String[] array = s.split("[-._]|(?=[abr])");

See Ideone Demo

Output:

[1, 18, 0, a]          //for input = "1.18.0a"