不明白为什么在填充此2d数组时为什么索引超出范围异常

Question

        while (scanner.hasNextLine()) {
            line = scanner.nextLine();
            if (line.charAt(0) != '#') {
                c++;
                // looking to get dimensions from file.
                // getting size of array from lines of input.
                dimensions = new int[c][4];

                // Split my file input into an array of tokens(strings)
                tokens = line.split(",");

                for (int i = 0; i < tokens.length; i++) {
                    // Parse strings to int.
                    dimtoke[i] = Integer.parseInt(tokens[i]);
                }

                int n = 0;
                for (int k = 0; k < dimensions.length; k++) {
                    for (int j = 0; j < dimensions[0].length; j++) {
                        // Error here when trying to put dimtoke into dimensions
                        (ERROR HERE)dimensions[k][j] = dimtoke[n];

                        n++;
                    }
                }
            }

The for loop to fill the dimensions array runs twice correctly, on the third iteration however, I am getting an ArrayIndexOutOfBounds:4 exception and I can't figure why. The size of the 2d array is correct, I need that counter n so that i can go through dimtoke array and it should reset itself each time through the while loop. (This is all contained in a try/catch block, but couldn't add the 'try' for formatting issues on this sight.)

Here's the stack trace.

java.lang.ArrayIndexOutOfBoundsException: 4
    at P1.readLineSegments(P1.java:49)
    at P1.main(P1.java:16)

Answer 1

You have n++ in the wrong spot.

int n = 0;
for (int k = 0; k < dimensions.length; k++) {
    for (int j = 0; j < dimensions[0].length; j++) {
        // Error here when trying to put dimtoke into dimensions
        (ERROR HERE)dimensions[k][j] = dimtoke[n];
    }
    n++; //it should be here
}

Where you have n++ it will go up 16 if it is a 4x4 array.

Answer 2

it can be dimensions[k][j] or dimtoke[n] . k is the length of dimension so it is out of question. j is 0..3 ( if it is as simple as code shows. so dimensions[0].length can be replaced with 4.)

the only problem is with dimtoke[n] and it seems size of your tokens are less than 4 * dimensions.length