Split a String into block of a specified length (expept the last)

Question

Let's say I have the following string:

String = "0123456789abcdefg";

How can I split it in blocks of 5, so that I get an array of string like

["01234", "56789", "abcde", "fg"]

Notice the last string is 2 characters long.

Is there a simple way to do so in Java?

Honestly, that would result in a very trivial code, a for-loop and a couple of String.substring() try yourself a bit first... — morgano, Jul 09 '14 at 02:33
Well, I don't have any code. I am asking this question hoping there was a function already provided in the language. — Gradient, Jul 09 '14 at 02:35
check this post: http://stackoverflow.com/questions/3760152/split-string-to-equal-length-substrings-in-java — , Jul 09 '14 at 02:36
@RafaelOsipov Thank you. I voted to close my question, as it is a duplicate of the one you linked. — Gradient, Jul 09 '14 at 02:40

drew moore · Answer 1 · 2014-07-11T03:19:26.627

3

//UNTESTED CODE!!
String in = "0123456789abcdefg";
List<String> blocks = new ArrayList<String>();

int i = 0;
for ( ; i < (in.length()-5) ; i += 5) { //while there are more than 5 characters remaining 
    blocks.add(in.substring(i, (i+5) ); 
}

blocks.add(in.substring(i, in.length()) //add any remaining characters

edited Jul 11 '14 at 03:19

answered Jul 09 '14 at 02:35

drew moore

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+1 for the comments in your code (although I insist the OP should have tried first) – morgano Jul 09 '14 at 02:38
@morgano yeah I agree completely - I just felt like doing it. OP, this answer was a disservice to you. Next time you run into a problem like this, do everything you can to figure it out yourself - that's how you learn to program, because programming *is* figuring things like this out. Come to SO when what you've figured out isn't working. – drew moore Jul 09 '14 at 02:43
1

interesting thing is that, doing micro-benchark between your solution and the one-liner answer in the duplicate question, yours runs at least 5 times faster... ha... just saying... makes sense as in the one-liner a regex must have to be internally compiled, so moral of the story is shorter code doesn't mean more efficient – morgano Jul 09 '14 at 03:20

score 1 · Answer 2 · answered Jul 09 '14 at 02:35

I guess that the substring method should be enough for your purpose, something like:

final int CHUNK_SIZE = 5;
List<String> chunks = new ArrayList<String>();

for (int i = 0; i*CHUNK_SIZE < string.length() - 1; ++i)
  chunks.add(string.substring(i*chunkSize,Math.min((i+1)*chunkSize, string.length())));

Split a String into block of a specified length (expept the last)

2 Answers2