Question

初学者JAVA程序疑问，帮我看看这个程序到底该怎么写。谢谢

public class GrandFather {
String haircolor;
String skincolor;
int hight;
int age = 70;
static String language = "Chinese";

static void yuyan(String a) {
language = a;
}

public void ageAdd() {
age++;
}

GrandFather() {
String a = null;
haircolor = a;
String b = null;
skincolor = b;
int c = 0;
hight = c;
int d = 0;
age = d;
}

public static void main(String [] args) {
GrandFather father = new GrandFather();
Father son = new Father();
System.out.println(GrandFather.language);
System.out.println(father.skincolor);
System.out.println(father.weightAdd());
System.out.println(son.visible);
System.out.println(son.haircolor);

}
}

class Father extends GrandFather {
int weight = 60;

private void weightAdd() {
weight++;
}

Father() {
super();
int w = 0;
weight = w;
}

}

class Son extends Father {
double visible = 5.0;

Son() {
super();
visible = 5.0;
}
}

帮我看看这个程序到底该怎么写。谢谢

Answer 1

System.out.println(father.weightAdd());
System.out.println(son.visible); 这两句编译肯定不通过~你是这么定义father是GrandFather的实例 而GrandFather类没有方法weightAdd()
son是Father的实例 而Father类也没有属性visible
那么编译错误
==========================================================
你可以这么改：
public static void main(String [] args) {
Father father = new Father();
Son son = new Son();
System.out.println(GrandFather.language);
System.out.println(father.skincolor);

father.weightAdd();
System.out.println(father.weight);
System.out.println(son.visible);
System.out.println(son.haircolor);

}
}
同时把Father类的 private void weightAdd() {
weight++;
}
修饰符 改成共有的 用于访问
public void weightAdd() {
weight++;
}
============================
PS： 说实话 这个程序的逻辑还有要表达的东西太模糊~ 回去多看看关于继承、多态的实现以及其效果 就好了~

Answer 2

哥哥不是跟你解决了吗 你还来百度！！！

刹那轻狂说的是对的

Answer 3

需求是什么？