Question

i have a problem to build following regex:
[1,2,3,4]

i found a work-around, but i think its ugly

String stringIds = "[1,2,3,4]";
stringIds = stringIds.replaceAll("\\[", ""); 
stringIds = stringIds.replaceAll("\\]", "");
String[] ids = stringIds.split("\\,");

Can someone help me please to build one regex, which i can use in the split function
Thanks for help

edit:
i want to get from this string “[1,2,3,4]” to an array with 4 entries. the entries are the 4 numbers in the string, so i need to eliminate “[“,”]” and “,”. the “,” isn’t the problem.
the first and last number contains [ or ]. so i needed the fix with replaceAll. But i think if i use in split a regex for “,”, i also can pass a regex which eliminates “[” “]” too. But i cant figure out, who this regex should look like.

Answer 1

This is almost what you’re looking for:

    String q = "[1,2,3,4]";
    String[] x = q.split("\\[|\\]|,");

The problem is that it produces an extra element at the beginning of the array due to the leading open bracket. You may not be able to do what you want with a single regex sans shenanigans. If you know the string always begins with an open bracket, you can remove it first.

The regex itself means “(split on) any open bracket, OR any closed bracket, OR any comma.”

Punctuation characters frequently have additional meanings in regular expressions. The double leading backslashes… ugh, the first backslash tells the Java String parser that the next backslash is not a special character (example: \n is a newline…) so \\ means “I want an honest to God backslash”. The next backslash tells the regexp engine that the next character ([ for example) is not a special regexp character. That makes me lol.