class Sup
{
private int i; //private one,not gonna get inherited.
void seti(int s) //this is to set i.but which i is going to set becz i is also in child class?
{
i=s;
System.out.println(i+"of sup class"); //to verify which i is changed
}
}
class Cid extends Sup //this is child class
{
private int i; //this is 2nd i. i want to change this i but isnt changing on call to the seti method
void changi(int h) //this one is working in changing the 2nd i.
{
i=h;
}
void showci()
{
System.out.println(i+"of Cid class");
}
}
class Test
{
public static void main(String[] args)
{
Cid ob= new Cid();
ob.seti(3); //to set i of Cid class but this sets Sup class i
ob.showci(); //result shows nothing changed from Cid class i
ob.changi(6); // this works as i wanted
ob.showci(); // now i can get the i changed of Cid class
}
}
请澄清一下，每当我们使用继承(或扩展)时，字段(除私有(private)变量和方法之外的变量和方法)是否会复制到子(或子)类，或者这些字段只能由子类访问？
最佳答案
通过此处对您问题的引用，您刚刚获得了对私有(private)变量“i”的访问权限，当您扩展 Sup 类时，您刚刚从sup 类中获得了 seti() 方法，该方法在父类(super class)中设置 var“i” 的值，但是如果您重写 Cid 类中的 seti() 方法，那么您将能够更改子类中 i 的值:
在这种情况下你需要使用
Sup s = new Cid();
s.seti(10); // this will change the value of i in subclass class 关于java - java中的继承.如何通过父类(super class)方法改变子类的变量值，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/29321058/