How to split an arraylist into two dimensional arrays?

Question

I am reading a text file into an arraylist and getting them by line but I want to split each line and put in a two dimensional array however String [][] array=lines.split(","); gives me an error.

File file=new File("text/file1.txt");
ArrayList<String> lines= (ArrayList<String>) FileUtils.readLines(file);
String [][] array=lines.split(",");

String [] array=lines.split(","); it will always return 1-dimension array. — Vishal Gajera, Dec 10 '15 at 07:35
I think this duplicate question http://stackoverflow.com/questions/10043209/convert-arraylist-into-2d-array-containing-varying-lengths-of-arrays — Piyush Gupta, Dec 10 '15 at 07:39

score 4 · Accepted Answer · answered Dec 10 '15 at 07:37

You must split each element of the List separately, since split operates on a String and returns a 1-dimensional String array :

File file=new File("text/file1.txt");
ArrayList<String> lines= (ArrayList<String>) FileUtils.readLines(file);
String [][] array=new String[lines.size()][];
for (int i=0;i<lines.size();i++)
    array[i]=lines.get(i).split(",");

score 0 · Answer 2 · answered Dec 10 '15 at 07:40

split() returns [] not [][]. try this :

File file=new File("text/file1.txt");
List<String> lines= (ArrayList<String>) FileUtils.readLines(file);
String [][] array= new String[lines.size()][];
int index = 0;
for (String line : lines) {
    array[index] = line.split(",");
    index++;
}

How to split an arraylist into two dimensional arrays?

2 Answers2