How to pass a double array(boolean[][]) between activities?

Question

I can\'t see to get a double boolean array to pass through to the another activity. I use putExtra and when I retrieve it and cast it to boolean[][], it states that

Answer 1

If you really require a 2-dimensional array, you can easily convert a 2-dimensional array into a single dimensional array for passing between Activities like so:

public boolean[] toOneDimension(boolean[][] input){
    boolean[] output = new boolean[input.length * input[0].length];

    for(int i = 0; i < input.length; i++){
        for(int j = 0; j < input[i].length; j++){
            output[i*j] = input[i][j];
        }
    }

    return output;
}

which you can then build back into a 2-dimensional array like so:

public boolean[][] toTwoDimensions(int dimensions, boolean[] input){

    boolean[][] output = new boolean[input.length / dimensions][dimensions];

    for(int i = 0; i < input.length; i++){
        output[i/dimensions][i % dimensions] = input[i];
    }

    return output;
}

then use like so:

public static void main(String[] args){
    int size = 10;

    Random rand = new Random();
    Tester tester = new Tester(); //example code holder
    boolean[][] value = new boolean[size+1][size];

    for(int i = 0; i < size+1; i++){
        for(int j = 0; j < size; j++){
            value[i][j] = rand.nextBoolean();
        }
    }


    boolean [][] output = tester.toTwoDimensions(size, tester.toOneDimension(value));

    for(int i = 0; i < size+1; i++){
        for(int j = 0; j < size; j++){
            assert value[i][j] == output[i][j];
        }
    }


}

The only requirement is that you need to know the dimension of your array before you flattened it.