Java Basic(59)-Class to Hold Objects

1.創建新class稱為Dog，Animal和Fish



2.創建新class稱為DogList 在src文件夾中

public class Fish extends Animal{

}

public class Animal {

}

public class Dog extends Animal{

}

public class DogList {

private Dog[] theList = new Dog[5];

private int i=0;

public void add(Dog d){

if(i<theList.length){

theList[i]=d;

System.out.println("Dog added at index "+i);

i++;

}

}

}

class apples{

public static void main(String[] args){

DogList DLO = new DogList();

Dog d = new Dog();

DLO.add(d);

}

}

這是運行時的結果:

Dog added at index 0