为什么可以在超类构造函数中用子类对象调用私有方法……？

Question

class ParentClass
{    
    double height;
    public ParentClass()
    {
       height=10;
       System.out.println("this : "+this.getClass().getName());
       showHeight();
    }
    private void showHeight()
    {
        System.out.println("Height is : "+height);
    }
}

class ChildClass extends ParentClass
{    
    double weight;
    public ChildClass(double weight)
    {
        this.weight=weight;
    }
}

public class CallingPrivateMethod
{    
    public static void main(String arg[])
    {
        ChildClass childObj=new ChildClass(32.65);
    }
}

This will print the following :

this : ChildClass

Height is : 10.0

Answer 1

You're not calling the private method from the subclass; it's being invoked by the superclass (ParentClass) in its constructor, and that constructor is in turn invoked from the subclass. It's no different than any other time a base class invokes a private method.