Question

Why do I get an NPE on the assignment of:

    mPyramid[row][column] = temp;

Here is my code:

    Block temp;
    Block[][] pyramid = new Block[mInput.length][];

    for (int i = 0; i < pyramid.length; i++) {
        pyramid[i] = new Block[mInput[i].length];
        for (int j = 0; j < pyramid[i].length; j++) {
            pyramid[i][j] = new Block();
        }
    }

    for (int row = 1; row < mInput.length; row++) {
        for (int column = 0; column < mInput[row].length; column++) {
            temp = new Block(mInput[row][column], null, null);
            mPyramid[row][column] = temp;

            setParents(row, column);
            temp.setPathNode(calculateDistance(temp));

        }
    }
}

Answer 1

It seems you’re creating the local variable pyramid and then referencing mPyramid.