不能夠訪問受保護的字段或方法在子調用

Question

我的程序如下：

package pack1; 

public class Parent { 
int i=0; 
protected j =1; 
public k = 2; 
} 

package pack2; 

import pack1.Parent; 
public class Child extends Parent { 

public static void main (String args[]) { 
    Child c1 = new Child(); 
    c1.j = 100; // This is working fine 

    Parent c2 = new Child(); 
    c2.j=200; // Compilation error 

} 
} 

我的問題是：爲什麼我們也不能夠與「C2」訪問保護成員在父類。

Answer 1

不能與被爭論的答案爲「是因爲規範是這麼說的」：

A protected member of a base class is accessible in a derived class only if the access occurs through the derived class type. 

，你將不得不作出成員內部（或公共）。