Question

I want to split a string into N number of 2char strings. I know I must use String.subSequence. However I want it to keep creating these until the string is > 2

Answer 1

Try this:

int n = 3;
String s = "abcdefghijkl";

System.out.println(Arrays.toString( s.split("(?<=\\G.{2})(?=.)", n + 1 ) ) );

//prints: [ab, cd, ef, ghijkl], i.e. you have 3 2-char groups and the rest

The regex works as follows: find any position after 2 characters (zero-width postive look behind (?<=...)) starting from the last match position (\G) and before at least one more character (zero-width positive look ahead (?=.)). This should not match the positions at the start and end of the string and thus n can be as big as you want without resulting in an empty string at the start or the end.

Edit: if you want to split as much as possible, just leave out the second parameter to split.

Example:

String digits = "123456789";

System.out.println(Arrays.toString( digits.split("(?<=\\G.{2})(?=.)" ) ) ); //no second parameter

//prints: [12, 34, 56, 78, 9]