Why does Java throw NullPointerException here?

Question

public class Test {

    public int [] x;

    public Test(int N)
    {
       int[] x = new int [N];
       for (int i=0;i

        

Answer 1

what you did is called shadowing you shadowed your field x with local variable x. so all you need to do is avoiding this:

int[] x = new int [N]; is wrong, if you want your field to initialize instead of a local variable then you could do something like : x = new int [N]; for more information read this