黑马程序员-多态的使用，基类和导出类中方法、属性的使用

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package Diversify;

//关于多态，多方求解之后方得到正确答案

import static Test_purview.print.*;

import Test_initalized.neum;

public class Test_diversifyTest1 {

public static void main(String[] args){

Cycle c = new Cycle();

print(" 车轮数："+c.ride(neum.Bicycle).wh);

Unicycle c1 = new Unicycle();

print(" 车轮数："+((Unicycle)c1.ride(neum.Unicycle)).wh);

print(" 车轮数："+((Unicycle)c1.ride(neum.Unicycle)).wh1);

// 依然有疑问，按照程序的执行来看得到的返回类型是Cycle，但是为什么是Cycle还是不是很了解，但是正确的做法就是这样

// 把返回的Cycle类型强制转换成Unicycle类型就能得到正确的wh了

// 向下面这样子会得到的结果是0而不是4,因为遵循就近原则，哪儿近就得到哪儿的

// print(" 车轮数："+c1.ride(neum.Unicycle).wh);

}

}

class Cycle{

int wh = 0;

public Cycle(){

print("This is in The class Cycle!");

}

public Cycle ride(Object o){

print("Class: "+ this);

return this;

}

}

class Unicycle extends Cycle{

int wh1 = 4;

public Unicycle(){

print("This is in The class Unicycle!");

}

public Unicycle ride(Unicycle o){

print("Class: "+ this);

return this;

}

}

class Bicycle extends Cycle{

int wh = 2;

public Bicycle(){

print("This is in The class Bicycle!");

}

}

class Tricycle extends Cycle{

int wh = 3;

public Tricycle(){

print("This is in The Tricycle!");

}

}

//Output：

//This is in The class Cycle!

//Class: Diversify.Cycle@61de33

// 车轮数：0

//This is in The class Cycle!

//This is in The class Unicycle!

//Class: Diversify.Unicycle@ca0b6

// 车轮数：0

//Class: Diversify.Unicycle@ca0b6

// 车轮数：4

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