【发布时间】：2015-08-28 04:44:24
【问题描述】：
好的，我有一个班级作业，要为老师编写的石头剪刀布程序创建 3 种预先确定的方法。但是，当我运行程序时，它会连续多次运行这些方法。我已经多次查看代码，但无法找出问题所在。
以下是老师提供的部分课程：
public class Game
{
public static void main (String[] args)
{
Scanner in = new Scanner (System.in);
RockPaperScissors rps = new RockPaperScissors (); //***Your class
int numGames = 0;
String userChoice = "";
String cpuChoice = "";
String winner = "";
int userWins = 0;
int cpuWins = 0;
System.out.println("Welcome to Rock, Paper, Scissors!\n");
//Get odd number of games
System.out.println("How many rounds would you like to play?");
numGames = in.nextInt();
while (numGames % 2 == 0) //Even number
{
System.out.println("Sorry, number of games must be odd. Please try again:");
numGames = in.nextInt();
}
//Flush the buffer
in.nextLine();
//Play the game for the number of rounds the user entered
for (int i = 1; i <= numGames; i++)
{
//Get the user and computer choices
userChoice = rps.getUserChoice(); //***Your method
cpuChoice = rps.getCPUChoice(); //***Your method
System.out.println("Computer chooses " + cpuChoice);
//Pick winner
winner = rps.pickWinner(userChoice, cpuChoice); //***Your method
if (winner.equalsIgnoreCase("Tie"))
{
System.out.println("It's a tie! Play again.");
numGames++;
}
else
{
if (winner.equalsIgnoreCase("User"))
{
userWins++;
}
else if (winner.equalsIgnoreCase("Computer"))
{
cpuWins++;
}
else
{
System.out.println("Error in picking winner");
}
System.out.println(winner + " wins!");
}
} //end for
//Print results
System.out.println("\nUser wins: " + userWins);
System.out.println("Computer wins: " + cpuWins);
if (userWins > cpuWins)
{
System.out.println("\nThe user won!");
}
if (cpuWins > userWins)
{
System.out.println("The computer won!");
}
//Close game
System.out.println("\nThank you for playing!");
} //end main
} //end class
这是我的代码，我假设问题出在哪里：
public class RockPaperScissors {
public String getUserChoice() {
Scanner sc = new Scanner (System.in);
System.out.println("Enter your choice:");
String userInput = sc.nextLine();
boolean end = true;
while (end == true){
//Checks for valid user responses
if (userInput.equals("rock") || userInput.equals("paper")|| userInput.equals("scissors")){
end = false;
}
else {
System.out.println("Invalid response. Please enter rock paper or scissors:");
userInput = sc.next();
}
}
return userInput;
}// end getUsechoice
public String getCPUChoice() {
String computerChoice = " ";
Random rand = new Random();
int randomNum = rand.nextInt(3) + 1;
if (randomNum == 1){
computerChoice = "rock";
}
else if (randomNum == 2){
computerChoice = "paper";
}
else if (randomNum == 3){
computerChoice = "scissors";
}
return computerChoice;
}
public String pickWinner(String userChoice, String cpuChoice) {
String result = " ";
if (getUserChoice().equalsIgnoreCase("rock")) {
if (getCPUChoice().equalsIgnoreCase("rock")){
result = "tie";
}
else if (getCPUChoice().equalsIgnoreCase("paper")){
result = "Computer";
}
else if (getCPUChoice().equalsIgnoreCase("scissors")){
result = "User";
}
}
else if (getUserChoice().equalsIgnoreCase("paper")){
if (getCPUChoice().equalsIgnoreCase("paper")){
result = "tie";
}
else if (getCPUChoice().equalsIgnoreCase("rock")){
result = "User";
}
else if (getCPUChoice().equalsIgnoreCase("scissors")){
result = "Computer";
}
}
else if (getUserChoice().equalsIgnoreCase("Scissors")){
if (getCPUChoice().equalsIgnoreCase("scissors")){
result = "tie";
}
else if (getCPUChoice().equalsIgnoreCase("rock")){
result = "Computer";
}
else if (getCPUChoice().equalsIgnoreCase("Paper")){
result = "User";
}
}
return result;
}//end pickWinner
}//end rockPaperScissors
以下是该程序的示例会话：
欢迎来到石头剪刀布！
你想玩几局？ 1 输入您的选择：摇滚 电脑选纸 输入你的选择：rock 输入你的选择：rock 电脑赢了！
用户获胜：0 计算机获胜：1 计算机获胜！
感谢您的参与！
在这里，我想知道为什么它会继续多次要求用户输入。它还运行其他方法，这就是为什么计算机在选择纸和石头的情况下获胜的原因。
好的，在我的程序的最后更改中添加了它现在可以正常运行：
public String pickWinner(String userChoice, String cpuChoice) {
String result = " ";
if (userChoice.equalsIgnoreCase("rock")) {
if (cpuChoice.equalsIgnoreCase("rock")){
result = "tie";
}
else if (cpuChoice.equalsIgnoreCase("paper")){
result = "Computer";
}
else if (cpuChoice.equalsIgnoreCase("scissors")){
result = "User";
}
}
else if (userChoice.equalsIgnoreCase("paper")){
if (cpuChoice.equalsIgnoreCase("paper")){
result = "tie";
}
else if (cpuChoice.equalsIgnoreCase("rock")){
result = "User";
}
else if (cpuChoice.equalsIgnoreCase("scissors")){
result = "Computer";
}
}
else if (userChoice.equalsIgnoreCase("Scissors")){
if (cpuChoice.equalsIgnoreCase("scissors")){
result = "tie";
}
else if (cpuChoice.equalsIgnoreCase("rock")){
result = "Computer";
}
else if (cpuChoice.equalsIgnoreCase("Paper")){
result = "User";
}
}
return result;
}//end pickWinner
问题似乎是，当我调用 getCPUChoice 或 getUserChoice 时，它会重新运行程序，然后更改最终答案。
【问题讨论】：
-
一点点优化：从
public static final String[] sChoices = {"rock","paper","scissors"}中选择 CPU。然后你可以在 {0;2} 中有一个随机的（我们称之为 pickNr）并通过return sChoices[pickNr];获得选择我会将随机对象设为类字段，因此你不会在每个对象中创建一个新对象计算机选择调用。那么 computerChoice 是一个 1-liner。 -
现在困扰我的是这个答案对未来的读者不是很有用。 “这个问题是由无法再复制的问题或简单的印刷错误引起的。”所以至少应该编辑它。
标签： java oop methods constructor