Question

I am trying to build an 2D array with the size of from 1D array and pupolate it with random numbers. Why don’t I get an output when I run this code below? There is no errors in my IDE:

public void raggedArray(){
    int maxRows = 3;
    int maxCols = 4;

    int [] onedArray = new int [maxRows];
        for (int i = 0; i < maxRows; i++){
        onedArray[i] = (int) ((Math.random() * 100) * maxCols);
    }

    int [][] twodArray = new int[maxRows][];
        for (int i = 0; i < maxRows; i++){
        twodArray[i] = new int[onedArray[i]];
    }

        for (int i = 0; i < twodArray.length; i++){
        for (int j = 0; j < twodArray[i].length; j++){
            twodArray[i][j] = (int) (Math.random() * 100);
        }
    }

    System.out.println("2 - The 2D array: ");
    for (int i = 0; i < twodArray.length; i++){
        for (int j = 0; j < twodArray[i].length; j++){
            System.out.print(twodArray[i][j] + " ");
        }
        System.out.println("");
    }

        }


} 

Answer 1

Your code compiles correctly, runs and outputs some numbers. Maybe raggedArray() isn’t called like Giacomo mentioned?

It might also be that the two-dimensional array is created incorrectly. I suppose this:

twodArray[i] = new int[onedArray[i]];

should be replaced with:

twodArray[i] = new int[maxCols];