如果没有程序错误，不确定有什么问题？

Question

我是java的新手，试图从这本书中学习一门课程并且我坚持制作一个程序。如果没有错误并且无法找到标记为guessdigit1＆amp;的符号，请继续告诉我。 2。

我一直说当我将鼠标悬停在符号旁边的错误对话框上时，guessdigit1和2是他们自己的类。任何的想法？ 谢谢！

package loterry;

import java.util.Scanner;

public class Loterry {
// This program creates two random numbers, and checks to see if your guess
    // makes the lottery win

    public static void main(String[] args) {
    Scanner input = new Scanner(System.in);
    System.out.println("Enter in your guess for loterry, two digits please");
        int lottery = (int)(Math.random()*100 /50);
        int guess = input.nextInt();
        int lotterydigit1= lottery /10;
        int lotterydigit2= lottery %10;

        // Get digits from guess
        int guessdigit1 = guess / 10;
        int guessdigit2 = guess % 10;

        System.out.println("The lottery number is " + lottery);

        if (guess == lottery)
            System.out.println("Exact Match: you win 10,000");
        else if (guessdigit2 == lotterydigit1 && guessdigit1 == lotterydigit2);
            System.out.println("Match all digits: you win 3,000");
        else if (guessdigit1 == lotterydigit1 
                     || guessdigit1 == lotterydigit2
                     || guessdigit2 == lotterydigit2
                     || guessdigit2 == lotterydigit2)
                  System.out.println("match one digit: you win 1,000");
                else
                  System.out.println("sorry no match");




    }
}

Answer 1

这是你的问题：

else if (guessdigit2 == lotterydigit1 && guessdigit1 == lotterydigit2);

删除分号（;）

else if (guessdigit2 == lotterydigit1 && guessdigit1 == lotterydigit2)

---

注意：建议您始终使用方括号if else {撰写}语句，以避免将来出现任何错误，当然还有在Java code conventions。 （有关括号问题的说明，请参阅this answer）

else if (guessdigit2 == lotterydigit1 && guessdigit1 == lotterydigit2){
     System.out.println("Match all digits: you win 3,000");
}

Answer 2

删除semicolon (;)以避免编译错误

使用if else语句中的curly braces "{ }"块来避免混淆

if (guess == lottery)
            System.out.println("Exact Match: you win 10,000");
        else if (guessdigit2 == lotterydigit1 && guessdigit1 == lotterydigit2); //->here

Answer 3

替换
else if (guessdigit2 == lotterydigit1 && guessdigit1 == lotterydigit2);

带

else if (guessdigit2 == lotterydigit1 && guessdigit1 == lotterydigit2)

在撰写{}时，您应该使用if else。它使clean code和clean code易于调试。

Answer 4

只需删除您在第一个结尾处放置的分号（;）。

只有语句的末尾应该有分号（;）

工作代码：

public static void main(String[] args) {
    Scanner input = new Scanner(System.in);
    System.out.println("Enter in your guess for loterry, two digits please");
        int lottery = (int)(Math.random()*100 /50);
        int guess = input.nextInt();
        int lotterydigit1= lottery /10;
        int lotterydigit2= lottery %10;

        // Get digits from guess
        int guessdigit1 = guess / 10;
        int guessdigit2 = guess % 10;

        System.out.println("The lottery number is " + lottery);

        if (guess == lottery)
            System.out.println("Exact Match: you win 10,000");
        else if (guessdigit2 == lotterydigit1 && guessdigit1 == lotterydigit2)
            System.out.println("Match all digits: you win 3,000");
        else if (guessdigit1 == lotterydigit1 
                     || guessdigit1 == lotterydigit2
                     || guessdigit2 == lotterydigit2
                     || guessdigit2 == lotterydigit2)
                  System.out.println("match one digit: you win 1,000");
                else
                  System.out.println("sorry no match");




    }

Answer 5

是的那个分号之后，如果声明是搞乱你的话。但严重的是，虽然我建议你在将来使用括号...它使代码看起来更整洁，从而更容易跟踪事物......相信我，它在处理更大的程序或在团队中工作时确实有帮助

Answer 6

在条件之后只需重新调用;并使用{}每个语句

请参阅此处docs

     if (guess == lottery){
//code here

}

        else if (guessdigit2 == lotterydigit1 && guessdigit1 == lotterydigit2){
//code here

}

        else if (guessdigit1 == lotterydigit1 
                     || guessdigit1 == lotterydigit2
                     || guessdigit2 == lotterydigit2
                     || guessdigit2 == lotterydigit2){
//code here

}

                else{
//code here

}