How to split element in an ArrayList in multidimensional arrayList

Question

I have the following:

[[Statistics (pH)], [ Upright Normal Recumbent Normal Total]]

I want to split the first element of the second element on whitespace so that I end up with:

[[Statistics (pH)], [Upright,Normal,Recumbent,Normal,Total]]

My code so far:

for (ArrayList<List<String>> row2 : StatspH) {
row2.get(1).get(0).split("\\s");
}

but nothing happens

Java strings are immutable. row2.get(1).get(0).split("\\s") splits the string, but you are discarding the returned String[]. — Andy Turner
– Andy Turner, Commented Apr 19, 2016 at 18:19
String methods are not mutators, in fact String itself in Java is immutable. split() will return a new instance of String[]. — 11thdimension
– 11thdimension, Commented Apr 19, 2016 at 18:19
Also, you'd need to trim before splitting to get that result. — Andy Turner
– Andy Turner, Commented Apr 19, 2016 at 18:21
Ok so how to replace the whole element with the new array from split? — Sebastian Zeki
– Sebastian Zeki, Commented Apr 19, 2016 at 18:27

Cliabhach · Accepted Answer · 2016-04-19 18:28:23Z

1

Java Strings are immutable, so you need to store the return value of split("\\s") in the correct List.

I recommend something like

for (ArrayList<List<String>> row2 : StatspH) {
    List<String> stats = row2.get(1);

    // remove() returns the object that was removed
    String allStats = stats.remove(0);

    Collections.addAll(stats, allStats.split("\\s"));
}

Note that we're removing the original string first, then adding all of the 'split' values.

answered Apr 19, 2016 at 18:28

Cliabhach

1,5802 gold badges12 silver badges21 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

How to split element in an ArrayList in multidimensional arrayList

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related