Test7.1

树上的第六章我看了一下，觉得好麻烦，就没有深入研究，题目也没有做，直接跳到第七章

这一题中，我定义了Fruit 和Banana两个类，Fruit相当于基类，Banana是派生类，派生类中定义了一个基类的引用然后对他初始化。。。

class Fruit

{private String color;
private double weight;
private int price;
//First fruit constructor
Fruit()
{System.out.println("A king of fruit");color="Red";weight=0;price=0;}
//second fruit constructor
Fruit(String c,double w,int p)
{System.out.println("A kind of fruit");color=c;weight=w;price=p;}


public String toString()
{
return 
"Color= "+color+"; Weight= "+weight+"; Price= "+price;
}
}


class Banana 
{
private String size;
private Fruit f;
//first banana constructor
Banana()
{
System.out.println("A banana ");
size="Big";
f=new Fruit();
}
//second banana constructor
Banana(String s,Fruit fr)
{System.out.println("A banana ");
size=s;
f=fr;
}
public String toString()
{
return
"Size= "+size+" "+f;
}
}


public class Test1
{
public static void main(String[] args) {
Fruit fu=new Fruit("Yellow",2.1,41);
System.out.println(fu);
Banana ba=new Banana("Small",fu);
System.out.println(ba);
}
}