使用面向對象的概念表示出下面的生活場景

我們的鬼畜java老師喜歡佈置課後作業，然後把代碼寫在紙上再上交

這次的習題是：

使用面向對象的概念表示出下面的生活場景：

小明去超市買東西，所有買到的東西都放在了購物車之中，最後到收銀臺一起結賬。

先貼下代碼，草草寫的。

interface Goods{					//使用接口表示商品
	public double getPrice();
	public String getName();
}

class Toys implements Goods{         //玩具區繼承接口Goods
	private String name;
	private double price;
	static String goodName = "玩具";
	public double getPrice(){
		return this.price;
	}
	public String getName() {
		return this.name;
	}
	Toys(String name,double price){
		this.name = name;
		this.price = price;
	}
};

class Clothes implements Goods{			//服裝區
	private String name;
	private double price;
	static String goodName = "服裝";
	public double getPrice(){
		return this.price;
	}
	public String getName() {
		return this.name;
	}
	Clothes(String name,double price){
		this.name = name;
		this.price = price;
	}
};

class Drinks implements Goods{		//飲品區
	private String name;
	private double price;
	static String goodName = "飲品";
	public double getPrice(){
		return this.price;
	}
	public String getName() {
		return this.name;
	}
	Drinks(String name,double price){
		this.name = name;
		this.price = price;
	}
};

class Foods implements Goods{	//食品區
	private String name;
	private double price;
	static String goodName = "食品";
	public double getPrice(){
		return this.price;
	}
	public String getName() {
		return this.name;
	}
	Foods(String name,double price){
		this.name = name;
		this.price = price;
	}
};

class ShopTotal{
	private Goods[] Good;           //模擬購物車
	private int foot;				//購買的商品數量
	private double total;
	static int len = 5; 
	ShopTotal(){
		this.Good = new Goods[len];
	}
	public void add(Goods good){		
		if(this.foot >= this.Good.length){		//當商品數大於購物車的容量就要進行擴容
			Goods[] goods = new Goods[this.Good.length+len];
			System.arraycopy(this.Good, 0, goods, 0, this.Good.length);
			this.Good = goods;
		}
		this.Good[this.foot] = good;
		this.foot++;
	}
	public double totalMoney(){
		for(int i = 0;i<this.foot;i++){
			total += Good[i].getPrice();
		}
		return this.total;
	}
	public int getNumber(){
		return this.foot;
	}
};



public class ShoppingMall {
	public static void main(String args[]){
		ShopTotal st = new ShopTotal();
		st.add(new Toys("手槍",25.5));
		st.add(new Toys("飛機",84.3));
		st.add(new Drinks("特倫舒（箱）",73.5));
		st.add(new Foods("樂事薯片",8.5));
		st.add(new Clothes("牛仔褲",120));
		st.add(new Clothes("白T",60));
		System.out.println("共購買"+st.getNumber()+"件商品,合計"+String.format("%.2f", st.totalMoney())+"元");
	}
}

寫得很簡單，這次作業學到了動態數組的擴容。