Confused with Java Objects

Question

I am a beginner with Java, and I am trying the following code:

public class MovieTestDrive {

    public static void main(String[] args) {
        Movie one = new Movie();
        one.title = "Gone with the Stock";
        one.playIt();
        System.out.println(one.title);   // Works!! one.title is equal to Dora

        Movie [] arr = new Movie[2];
        arr[0].playIt();
        System.out.println(arr[0].title); //Error: Null Pointer Exception

    }
}


class Movie {

        String title;

        void playIt() {
             title = "Dora";
        }

 }

Why does the code works in the assignment of a primitive variable while it doesn't when using an array?

Answer 1

Because all you have in arr is an array of object references, but they're not initialized to point at any actual objects.

You also need to do:

arr[0] = new Movie();
arr[1] = new Movie();

Answer 2

Nothing is in your movie array yet. You need to put objects in your array before you can act upon them.

Between "Movie [] arr = new Movie[2];" and "arr[0].playIt();", you need to assign Movie objects to your array in order to perform the .playIt() function and have anything actually occur.