Java 如何组合if/else语句

基本上，这个程序在一台计算机之间扮演一个骰子角色，然后显示谁得分更高。所以在我最后一次的if/else声明中，主要的区别是你赢了，还是你输了。有没有什么方法可以让我把它组合起来，这样更干净？我试着把它组合起来，但想不出来。有什么想法吗？谢谢你

//import scanner and random
import java.util.Random;
import java.util.Scanner;

//declare variables and methods
class Main {
int userOne, userTwo, compOne, compTwo, userTotal, compTotal;
char playAgain;
Scanner scan = new Scanner(System.in);
Random gen = new Random();

  //method to run entire program
  public void runProgram()
  {
    int r=1;
    //this will run the roll of the dice for the user and the computer
    for(r=1; r<2;)
    {
    System.out.println("Your turn:");
    userOne = gen.nextInt(6)+1;
    System.out.println("Your first roll was: " + userOne);
    userTwo = gen.nextInt(6)+1;
    System.out.println("Your second roll was: " + userTwo);
    userTotal = userOne + userTwo;
    System.out.println("Your total of the two rolls was: " + userTotal);

    System.out.println("Computers turn:");
    compOne = gen.nextInt(6)+1;
    System.out.println("The computers first roll was: " + compOne);
    compTwo = gen.nextInt(6)+1;
    System.out.println("The computers second roll was: " + compTwo);
    compTotal = compOne + compTwo;
    System.out.println("The computers total of the two rolls was: " + compTotal);

    //This determines win or loss and lets the user choose if they want to play again
    if (userTotal > compTotal)
    {
      //winning- statement to ask if the user wants to play again
      System.out.println("You won! Would you like to play again? Respond with Yes or No: ");
      playAgain = scan.next().charAt(0);
      if ((String.valueOf(playAgain)).equalsIgnoreCase("y") == true)
      {
        r=1;
      }
      else
      {
        r=2;
      }
    }
    else
    {
      //losing- statement to ask if the user wants to play again
      System.out.println("Sorry, you lost. Would you like to play again? Yes or No?");
      playAgain = scan.next().charAt(0);

      if ((String.valueOf(playAgain)).equalsIgnoreCase("y") == true)
      {
        r=1;
      }
      else
      {
        r=2;
      }
    }
    }
  }

public static void main(String[] args) {
    Main prog = new Main();
    prog.runProgram();
  }
}

//导入扫描仪和随机
导入java.util.Random；
导入java.util.Scanner；
//声明变量和方法
班长{
int userOne，userTwo，compOne，compTwo，userTotal，compTotal；
再次播放；
扫描仪扫描=新扫描仪（System.in）；
Random gen=新的Random（）；
//方法来运行整个程序
公共程序（）
{
int r=1；
//这将为用户和计算机运行掷骰子
对于（r=1；r合计）
{
//获胜-询问用户是否想再次玩的声明
System.out.println（“你赢了！你想再玩一次吗？回答是或否：”）；
playreach=scan.next（）.charAt（0）；
if（（String.valueOf（playreach））.equalsIgnoreCase（“y”）==true）
{
r=1；
}
其他的
{
r=2；
}
}
其他的
{
//losing-询问用户是否希望再次播放的语句
System.out.println（“对不起，您输了。您想再玩一次吗？是还是否？”）；
playreach=scan.next（）.charAt（0）；
if（（String.valueOf（playreach））.equalsIgnoreCase（“y”）==true）
{
r=1；
}
其他的
{
r=2；
}
}
}
}
公共静态void main（字符串[]args）{
主程序=新主程序（）；
prog.runProgram（）；
}
}

正如khelwood所建议的，您可以在win/loss if语句之外组合播放消息

if (userTotal > compTotal) {
    System.out.println("You won!");
} else {
    System.out.println("Sorry, you lost.");
}

System.out.println("Would you like to play again? Yes or No?");
playAgain = scan.next().charAt(0);

if ((String.valueOf(playAgain)).equalsIgnoreCase("y")) {
    r = 1;
} else {
    r = 2;
}

---

我想说的是，使用此代码可以改进的一点是避免复制和粘贴代码。永远不要重复你自己

第二件需要改进的事情是，您可以在（（String.valueOf（playreach））.equalsIgnoreCase（“y”）时执行

循环，而不是执行奇怪的
for
循环。这样，您就不会有一个令人困惑的r变量，该变量基于playreach是否为“y”

  public void runProgram()
  {
    playAgain = 'y';
    //this will run the roll of the dice for the user and the computer
    while ((String.valueOf(playAgain)).equalsIgnoreCase("y") == true)
    {
        System.out.println("Your turn:");
        userOne = gen.nextInt(6)+1;
        System.out.println("Your first roll was: " + userOne);
        userTwo = gen.nextInt(6)+1;
        System.out.println("Your second roll was: " + userTwo);
        userTotal = userOne + userTwo;
        System.out.println("Your total of the two rolls was: " + userTotal);

        System.out.println("Computers turn:");
        compOne = gen.nextInt(6)+1;
        System.out.println("The computers first roll was: " + compOne);
        compTwo = gen.nextInt(6)+1;
        System.out.println("The computers second roll was: " + compTwo);
        compTotal = compOne + compTwo;
        System.out.println("The computers total of the two rolls was: " + compTotal);

        //This determines win or loss and lets the user choose if they want to play again
        if (userTotal > compTotal)
        {
            //winning- statement to ask if the user wants to play again
            System.out.println("You won! Would you like to play again? Respond with Yes or No: ");
        }
        else
        {
            //losing- statement to ask if the user wants to play again
            System.out.println("Sorry, you lost. Would you like to play again? Yes or No?");
        }
          
        playAgain = scan.next().charAt(0);
    }
}

进行这些更改可以使您的代码更清楚地了解您打算让程序做什么。
只需将重复的内容移出if-else语句。

另外，
==true
可以从
if（）
中删除，因为它已经返回布尔值

if (userTotal > compTotal){
    //winning- statement to ask if the user wants to play again
    System.out.println("You won! Would you like to play again? Respond with Yes or No: ");
}else{
    //losing- statement to ask if the user wants to play again
    System.out.println("Sorry, you lost. Would you like to play again? Yes or No?");
}

playAgain = scan.next().charAt(0);

if ((String.valueOf(playAgain)).equalsIgnoreCase("y")){
    r=1;
}else{
    r=2;
}

是的，通过将负责确定是否再次运行程序的代码移到if/else语句之外，因为用户赢了或输了都无关紧要，最后问题仍然是：是否要再次播放？因此，无论结果如何，这种逻辑都不应该被负责确定谁是一个的逻辑所封装（因为同样，这是不相关的）

第二件事，这是完全可选的，但它会使您的代码更干净，似乎您使用if/else语句只是为了确定哪些值应该分配给变量，在这种情况下，使用

还有一件事，当使用返回布尔值true/false的方法时，没有必要键入==false/true，因为函数本身已经这样做了，例如equalsIgnoreCase（）函数

因此，在所有这些编辑之后，您的代码如下所示：

    //import scanner and random
import java.util.Random;
import java.util.Scanner;

//declare variables and methods
class Main {
int userOne, userTwo, compOne, compTwo, userTotal, compTotal;
char playAgain;
Scanner scan = new Scanner(System.in);
Random gen = new Random();
String result;

  //method to run entire program
  public void runProgram() {
    int r=1;
    //this will run the roll of the dice for the user and the computer
    for(r=1; r<2;)
    {
    System.out.println("Your turn:");
    userOne = gen.nextInt(6)+1;
    System.out.println("Your first roll was: " + userOne);
    userTwo = gen.nextInt(6)+1;
    System.out.println("Your second roll was: " + userTwo);
    userTotal = userOne + userTwo;
    System.out.println("Your total of the two rolls was: " + userTotal);

    System.out.println("Computers turn:");
    compOne = gen.nextInt(6)+1;
    System.out.println("The computers first roll was: " + compOne);
    compTwo = gen.nextInt(6)+1;
    System.out.println("The computers second roll was: " + compTwo);
    compTotal = compOne + compTwo;
    System.out.println("The computers total of the two rolls was: " + compTotal);

    //This determines win or loss and lets the user choose if they want to play again
      result = userTotal > compTotal ?  "won! " :  "lost. ";

      // Ternary operator
      System.out.println("you " + result + "Would you like to play again? Yes or No?");

      playAgain = scan.next().charAt(0);

      // another ternary operator
      r = String.valueOf(playAgain).equalsIgnoreCase("y") ? 1 : 2;

    }
  }


public static void main(String[] args) {
    Main prog = new Main();
    prog.runProgram();
  }
} 

//导入扫描仪和随机
导入java.util.Random；
导入java.util.Scanner；
//声明变量和方法
班长{
int userOne，userTwo，compOne，compTwo，userTotal，compTotal；
再次播放；
扫描仪扫描=新扫描仪（System.in）；
Random gen=新的Random（）；
字符串结果；
//方法来运行整个程序
公共程序（）{
int r=1；
//这将为用户和计算机运行掷骰子
对于（r=1；r总计？“赢了！”：“输了”；
//三元运算符
System.out.println（“您”+结果+“您想再次播放吗？是还是否？”）；
playreach=scan.next（）.charAt（0）；
//另一个三元算子
r=String.valueOf（再次播放）.equalsIgnoreCase（“y”）？1:2；
}
}
公共静态void main（字符串[]args）{
主程序=新主程序（）；
prog.runProgram（）；
}
} 
为什么不将两个分支中的所有内容都移动到else块之后呢？使用
while（true）代替
r
，并且当他们不想再次播放时，
中断。请删除
==true
equalsIgnoreCase
已返回boolean@MrCodingB这是真的。然而，有些人可能会说，包含
==true
有助于提高可读性。是的，但大多数约定告诉您不要使用它，因此最好不要发布它回答