Question

我正在为我的课程设计一个应该模拟彩票游戏的程序。我应该设计一种生成随机抽奖号码的方法，一种询问和存储用户数量选择的方法，一种比较数组以查找数量相同的方法，然后我应该将它们全部称为备份到main方法，并创建我的输出语句，其中包含一些if语句，用于确定特定匹配数量的奖项。

这是我到目前为止所拥有的

import java.util.*;


public class LotteryGame {
/**
  The main method is the program's starting point 
*/
public static void main(String[] args){

  int NUM_DIGITS = 5;

  int[] userDigits = new int[5];
  int[] lotteryNumbers = new int[5];
  int sameNum;

  generateNumbers(lotteryNumbers);
  getUserData(userDigits);
  compareArrays();


  System.out.println("Lottery numbers: " + lotteryNumbers[0] + " " +
  lotteryNumbers[1] + " " + lotteryNumbers[2] + " " + lotteryNumbers[3] +
  " " + lotteryNumbers[4] + " ");

  System.out.println("Player numbers:  " + userDigits[0] + " " + userDigits[1] + " " + userDigits[2] + " " + userDigits[3] + " " + userDigits[4] + " ");
  System.out.println("Number of matching digits: " + sameNum);

  if (sameNum == 5){
     System.out.println("GRAND PRIZE WINNER - $5 MILLION!!");
     }

  if (sameNum == 4){
     System.out.println("SUPER PRIZE WINNER - $500,000!!");
     }

  if (sameNum == 3){
     System.out.println("GOOD PRIZE WINNER - $5,000!!");
     }

  if (sameNum == 2){
     System.out.println("NICE PRIZE WINNER - $500!!");
     } 

  if (sameNum == 1){
     System.out.println("WINNER - $5!!");
  }
  if (sameNum ==0){
     System.out.println("No matching numbers - better luck next time");
     }


} 
public static int generateNumbers(int [] lotteryNumbers){


  Random randNum = new Random();

  lotteryNumbers[0] = randNum.nextInt(10);
  lotteryNumbers[1] = randNum.nextInt(10);
  lotteryNumbers[2] = randNum.nextInt(10);  
  lotteryNumbers[3] = randNum.nextInt(10);
  lotteryNumbers[4] = randNum.nextInt(10);

  return lotteryNumbers[4];
}

public static int getUserData (int [] userDigits){
  Scanner keyboard = new Scanner(System.in);

  System.out.print("Enter digit 1: ");
  userDigits[0] = keyboard.nextInt();
  System.out.print("Enter digit 2: ");
  userDigits[1] = keyboard.nextInt();
  System.out.print("Enter digit 3: ");
  userDigits[2] = keyboard.nextInt();
  System.out.print("Enter digit 4: ");
  userDigits[3] = keyboard.nextInt();
  System.out.print("Enter digit 5: ");
  userDigits[4] = keyboard.nextInt();

  return userDigits[4];

}

public static int compareArrays (int [] userDigits, 
                                    int [] lotteryNumbers){

 int sameNum = 0;

 for (int i = 0; i < 5; i++){

     for (int x = 0; x < 5; x++){

         if (lotteryNumbers[i] == userDigits[x]){
           sameNum++;
           }
              return sameNum;
              }                           

              return sameNum;                         
  }
              return sameNum;

 }

}

我对数组（以及Java）非常陌生，所以我的问题出在我的return / call语句中。请原谅我的空间编码风格和我所犯的任何明显错误。任何提示，建议，解决方案，或者如果您发现我有什么问题请告诉我。谢谢！

Answer 1

我已根据您需要的更改更新了您的代码。

为初始化程序添加了NUM_DIGITS
关闭扫描仪
删除比较方法中的早期退货
将比较方法的返回值指定给sameNum
设置生成的返回值，并将方法设置为void

其他建议可能是您想要合并的内容（例如开关/案例）。

import java.util.Random;
import java.util.Scanner;

public class App {

    public static void main(String[] args) {

        int NUM_DIGITS = 5;

        int[] userDigits = new int[NUM_DIGITS];
        int[] lotteryNumbers = new int[NUM_DIGITS];
        int sameNum;

        generateNumbers(lotteryNumbers);
        getUserData(userDigits);
        sameNum = compareArrays(lotteryNumbers, userDigits);

        System.out.println("Lottery numbers: " + lotteryNumbers[0] + " "
                + lotteryNumbers[1] + " " + lotteryNumbers[2] + " "
                + lotteryNumbers[3] + " " + lotteryNumbers[4] + " ");

        System.out.println("Player numbers:  " + userDigits[0] + " "
                + userDigits[1] + " " + userDigits[2] + " " + userDigits[3]
                + " " + userDigits[4] + " ");
        System.out.println("Number of matching digits: " + sameNum);

        if (sameNum == 5) {
            System.out.println("GRAND PRIZE WINNER - $5 MILLION!!");
        }

        if (sameNum == 4) {
            System.out.println("SUPER PRIZE WINNER - $500,000!!");
        }

        if (sameNum == 3) {
            System.out.println("GOOD PRIZE WINNER - $5,000!!");
        }

        if (sameNum == 2) {
            System.out.println("NICE PRIZE WINNER - $500!!");
        }

        if (sameNum == 1) {
            System.out.println("WINNER - $5!!");
        }
        if (sameNum == 0) {
            System.out.println("No matching numbers - better luck next time");
        }

    }

    public static void generateNumbers(int[] lotteryNumbers) {

        Random randNum = new Random();

        lotteryNumbers[0] = randNum.nextInt(10);
        lotteryNumbers[1] = randNum.nextInt(10);
        lotteryNumbers[2] = randNum.nextInt(10);
        lotteryNumbers[3] = randNum.nextInt(10);
        lotteryNumbers[4] = randNum.nextInt(10);

        return lotteryNumbers[4];
    }

    public static void getUserData(int[] userDigits) {
        Scanner keyboard = new Scanner(System.in);

        System.out.print("Enter digit 1: ");
        userDigits[0] = keyboard.nextInt();
        System.out.print("Enter digit 2: ");
        userDigits[1] = keyboard.nextInt();
        System.out.print("Enter digit 3: ");
        userDigits[2] = keyboard.nextInt();
        System.out.print("Enter digit 4: ");
        userDigits[3] = keyboard.nextInt();
        System.out.print("Enter digit 5: ");
        userDigits[4] = keyboard.nextInt();

        keyboard.close();

        return userDigits[4];
    }

    public static int compareArrays(int[] userDigits, int[] lotteryNumbers) {
        int sameNum = 0;

        for (int i = 0; i < 5; i++) {
            for (int x = 0; x < 5; x++) {
                if (lotteryNumbers[i] == userDigits[x]) {
                    sameNum++;
                }
            }
        }
        return sameNum;
    }

}

Answer 2

请记住，randNum.nextInt（10）会为您提供从0到9的彩票号码。您可以使用for循环将随机数分配给lotteryNumbers数组更容易。此外，您应该确保随机抽奖号码不会重复。

在你的compareArrays函数中，只需在最外面的for循环之后返回一个sameNum调用，否则它将不会使用正确的匹配数字进行更新。您需要为compareArrays（）提供正确的参数（userDigits和lotteryNumbers），并将sameNum设置为等于此结果。

Answer 3

您可能会觉得有用的几点：

您可能希望使用NUM_DIGITS来启动数组，因为这是命名常量的全部要点：
```
int[] userDigits = new int[NUM_DIGITS];
int[] lotteryNumbers = new int[NUM_DIGITS];
```
您可以使用Arrays.toString()输出数组，例如：
```
System.out.println(Arrays.toString(lotteryNumbers));
```

使用if代替多个switch，加上不重复整个print语句，只分配不同的部分：

String prize = "";
switch (sameNum) {
    case 5:  prize = "GRAND PRIZE WINNER - $5 MILLION!!";
             break;
    case 4:  prize = "SUPER PRIZE WINNER - $500,000!!";
             break;
    case 3:  prize = "GOOD PRIZE WINNER - $5,000!!";
             break;
    case 2:  prize = "NICE PRIZE WINNER - $500!!";
             break;
    case 1:  prize = "WINNER - $5!!";
             break;
    case 0:  prize = "No matching numbers - better luck next time";
             break;
    default: prize = "Something weird happened";
}
System.out.println(prize);

Java彩票阵列计划

3 个答案: