OOD - Object Oriented Design 面向对象设计实例

OOD 面向对象设计有很大的几率出现在小公司的面试上，在youtube上找了一个很好的教程来和大家分享一下。

问题： OOD 思想设计两人投掷硬币的游戏。

步骤一： 准备documentation

游戏介绍：随机选择一个玩家，令该玩家预测硬币的正反面，另一个玩家获得和第一个玩家相反的选项。开始投掷硬币，预测正确的赢。

Actors： 1. 玩家A2. 玩家B  3. 硬币 4. 掷硬币游戏

根据以上信息我们可以画出object model.  这个决定我们要创建多少个实体类。

根据游戏规则以及流程，我们可以画出类图。

步骤二：代码实现

Player class. 

public class Player {private String Name;private String CoinOption;public String[] coinValue = {"Heads","Tails"}; Player(String name){this.Name = name;}public String getCoinOption(){return this.CoinOption;}public void setCoinOption(String opponentFlip){this.CoinOption = (opponentFlip.equals("Heads"))?"Tails":"Heads";}public String getRandCoinOption(){int randNum = (Math.random()<0.5)?0:1;this.CoinOption = this.coinValue[randNum];return this.CoinOption;}public void didPlayerWin(String winningFlip){if(this.CoinOption.equals(winningFlip)){System.out.println(this.Name + " won with flip of " + this.CoinOption);}elseSystem.out.println(this.Name + " lost " + this.CoinOption);}}

Coin Class

public class Coin {private String coinOption = "";public String[] coinValue = {"Heads","Tails"};Coin(){int randNum = (Math.random() < 0.5)?0:1;this.coinOption = this.coinValue[randNum];}public String getCoinOption(){return this.coinOption;}}

CoinGame Class

public class CoinGame { Player[] players = new Player[2]; Coin theCoin = new Coin();  CoinGame(String p1Name, String p2Name){  players[0] = new Player(p1Name); players[1] = new Player(p2Name); }  public void startGame(){  int randNum = Math.random()<0.5?0:1; String playersPick = players[randNum].getRandCoinOption();  int opponentsIndex = (randNum == 1)?0:1; players[opponentsIndex].setCoinOption(playersPick);  String winningFlip = theCoin.getCoinOption();  players[0].didPlayerWin(winningFlip); players[1].didPlayerWin(winningFlip); }}

main 测试类

public class main {public static void main(String[] args){CoinGame theCoinGame = new CoinGame("Huazhe", "meigtong");String userAnswer;do{theCoinGame.startGame();System.out.println("Play again?y/n");Scanner input = new Scanner(System.in);userAnswer = input.nextLine();}while(userAnswer.equals("y"));}}

学习心得：个人感觉 OOD 体现的更多的是对问题由大到小进行分割的思想，将大的问题进行简化成一部分模块( object )， 然后对各个模块之间的交流进行组合已达到解决问题的最终目的。