我如何创建抽象 class 的对象？

Question

1. Why GeometricObject[] abstractObjects = new GeometricObject[10]; don't cause error that I create objects of an abstract class?
2. What's the difference between A[] objects; and A[] objects = new A[7];

public class Test
{
    public static void main(String[] args)
    {
        int[] numbers = new int[8];
        A[] objects = new A[7];
        GeometricObject[] abstractObjects = new GeometricObject[10];
        System.out.println(numbers[3]); // prints 0
        System.out.println(objects[4]); // prints null
        System.out.println(abstractObjects[6]); // prints null
    }
}

abstract class GeometricObject {}

class A
{
    public int number;
    A()
    {
        number = 13;
    }
}

Answer 1

 GeometricObject[] abstractObjects = new GeometricObject[10];

you are not creating object of GeometricObject here. You are creating an object of an array(of type GeometricObject class ).

What's the difference between A[] objects; and A[] objects = new A[7];

A[] objects = new A[2] is divided in two parts

A[] objects - its called deceleration of object.

new A[7] - called initialization of object