I'm trying to read a text file and put each comma separated value in an array and put all of them inside a 2d array.But the code I have right now puts the whole line in the array

Scanner sc = new Scanner(new BufferedReader(new FileReader(path)));
        int rows = 3;
        int columns = 1;
        String[][] myArray = new String[rows][columns];
        while (sc.hasNextLine()) {
            for (int i = 0; i < myArray.length; i  ) {
                String[] line = sc.nextLine().trim().split(" "   ",");
                for (int j = 0; j < line.length; j  ) {
                    myArray[i][j] = line[j];
                }
            }
        }
        System.out.println(Arrays.deepToString(myArray));

This is the text file:

A6,A7
F2,F3
F6,G6

Output

[[A6,A7], [F2,F3], [F6,G6]]

Expected Output

[[A6],[A7],[F2],[F3],[F6],[G6]]

CodePudding user response：

i think you have to double the rows size and for each line just put one element and increment the i

CodePudding user response：

The problem is that you are assigning the entire 2D array instead of just each item.

Here are several alternatives.

Use Files.lines to stream the file.
splitting on a comma creates the 1D array of two elements for each line
flatMap that to stream each item.
that map that to an array of one item.
then just store them in a 2D array.

String[][] array = null;
try {
    array = Files.lines(Path.of("f:/MyInfo.txt"))
            .flatMap(line->Arrays.stream(line.split(","))
                 .map(item->new String[]{item}))
            .toArray(String[][]::new);
} catch (IOException ioe) {
    ioe.printStackTrace();
}
if (array != null) {
    System.out.println(Arrays.deepToString(array));
}

prints

[[A6], [A7], [F2], [F3], [F6], [G6]]

Here is an approach similar to yours.

List<String[]> list = new ArrayList<>();
try {
    Scanner scanner = new Scanner(new File("f:/MyInfo.txt"));
    while (scanner.hasNextLine()) {
        String[] arr = scanner.nextLine().split(",");
        for (String item : arr) {
            list.add(new String[]{item});
        }
    }
} catch (IOException ioe) {
    ioe.printStackTrace();
}

There is no deepToString for Lists so you either iterate it or convert to a 2D array.

String[][] ar = list.toArray(String[][]::new);
System.out.println(Arrays.deepToString(ar));

prints

[[A6], [A7], [F2], [F3], [F6], [G6]]