第一版：
把每种动物都定义为一个类，漏洞大，每天加一种动物或者动物数量发生变化都会需要对代码进行调整
每种动物的喂食函数名也不同
package homework;
public class text
{
public static void main(String args[])
{
Feeder f = new Feeder("小王");
f.feedLion(new Lion());
for (int i = 0; i < 10; i++)
{
f.feedMonkey(new Monkey());
}
for (int i = 0; i < 5; i++)
{
f.feedPigeon(new Pigeon());
}
}
}
class Feeder
{
public String name;
public Feeder(String name)
{
this.name = name;
}
public void feedLion(Lion l)
{
l.eat();
}
public void feedPigeon(Pigeon p)
{
p.eat();
}
public void feedMonkey(Monkey m)
{
m.eat();
}
}
class Lion
{
public void eat()
{
System.out.println("吃肉");
}
}
class Monkey
{
public void eat()
{
System.out.println("吃香蕉");
}
}
class Pigeon
{
public void eat()
{
System.out.println("吃大米");
}
}
第二版：
相比于第一版来说，定义了一个抽象类，统一了各种动物喂食的函数，使得主函数变得更加的简洁
package homework;
public class text
{
public static void main(String args[])
{
Feeder f = new Feeder("小王");
f.feedAnimal(new Lion());
for (int i = 0; i < 10; i++)
{
f.feedAnimal(new Monkey());
}
for (int i = 0; i < 5; i++)
{
f.feedAnimal(new Pigeon());
}
}
}
class Feeder
{
public String name;
Feeder(String name)
{
this.name = name;
}
public void feedAnimal(Animal an)
{
an.eat();
}
}
//定义抽象类作为父类
abstract class Animal
{
//抽象函数eat
public abstract void eat();
}
//在下面定义各种动物，继承上面的抽象类
class Lion extends Animal
{
public void eat()
{
System.out.println("吃肉·");
}
}
class Monkey extends Animal
{
public void eat()
{
System.out.println("吃香蕉");
}
}
class Pigeon extends Animal
{
public void eat()
{
System.out.println("吃大米");
}
}
第三版：
利用了增强for循环，将各种动物都统一的存在一个Animal数组之中，代码更简洁，省去了调用喂食函数时的循环
package homework;
public class text {
public static void main(String args[]) {
Feeder f = new Feeder("小王");
Animal[] ans = new Animal[16];
//将各种动物排成一个数组
ans[0] = new Lion();
for (int i = 0; i < 10; i++) {
ans[1 + i] = new Monkey();
}
for (int i = 0; i < 5; i++) {
ans[11 + i] = new Pigeon();
}
f.feedAnimals(ans);
}
}
class Feeder {
public String name;
Feeder(String name) {
this.name = name;
}
public void feedAnimals(Animal[] ans) {
for (Animal an : ans) {
an.eat();
}
}
}
abstract class Animal {
public abstract void eat();
}
class Lion extends Animal {
public void eat() {
System.out.println("吃肉");
}
}
class Monkey extends Animal {
public void eat() {
System.out.println("吃香蕉");
}
}
class Pigeon extends Animal {
public void eat() {
System.out.println("吃大米");
}
}
第四版：
利用了vector容器，vector容器可以动态的添加数组内容，若有动物数量发生变化，更加容易调整。
package homework;
import java.util.Vector;
public class text {
public static void main(String args[]) {
Feeder f = new Feeder("小王");
Vector<Animal> ans = new Vector<Animal>();
ans.add(new Lion());
for (int i = 0; i < 10; i++) {
ans.add(new Monkey());
}
for (int i = 0; i < 5; i++) {
ans.add(new Pigeon());
}
f.feedAnimals(ans);
}
}
class Feeder {
public String name;
Feeder(String name) {
this.name = name;
}
public void feedAnimals(Vector<Animal> ans) {
for (Animal an : ans) {
an.eat();
}
}
}
abstract class Animal {
public abstract void eat();
}
class Lion extends Animal {
public void eat() {
System.out.println("吃肉");
}
}
class Monkey extends Animal {
public void eat() {
System.out.println("吃香蕉");
}
}
class Pigeon extends Animal {
public void eat() {
System.out.println("吃大米");
}
}
标签：eat,void,动物园,public,管理员,Animal,10.11,new,class From： https://www.cnblogs.com/xuxingkai/p/17758130.html