Question

对于我的程序，我想要一个询问学生人数，询问分数的东西，然后显示其中有多少分数是A，B，C等的输出。因此，如果我输入5个学生，我应该能够输入这5个分数，然后它将显示相应的成绩。取而代之的是，它在输入一个分数之后显示相应的分数，然后要求另一个分数。

//Declarations
    int A=0,B=0,C=0,D=0,F=0, score,I, students;
    I=1;

    System.out.println("How many students are in your class: ");
    students = input.nextInt();
    while (I<=students) {
    System.out.println("enter a score:");
    score=input.nextInt();


    if(score >= 90 && score <= 100)
        A++;
    else if(score>=80 && score<=89)
        B++;
    else if(score>=70 && score<=79)
        C++;
    else if(score>=60 && score<=69)
        D++;
    else if(score>=0 && score<=59)
        F++;


       System.out.println("Total number of A's:"+ A);
       System.out.println("Total number of B's:"+ B);
       System.out.println("Total number of C's:"+ C);
       System.out.println("Total number of D's:"+ D);
       System.out.println("Total number of F's:"+ F);


}

}}

Answer 1

简而言之-while循环的范围需要更小：

详细信息：对于每个学生，您要处理他们的考试成绩，增加几个变量之一。完全完成操作后（例如退出循环！）-您想要总结结果。

//Declarations
    int A=0,B=0,C=0,D=0,F=0, score,I, students;
    I=1;

    System.out.println("How many students are in your class: ");
    students = input.nextInt();
    while (I<=students) { // <-- separate unrelated problem where you aren't iterating properly
        System.out.println("enter a score:");
        score=input.nextInt();


        if(score >= 90 && score <= 100)
            A++;
        else if(score>=80 && score<=89)
            B++;
        else if(score>=70 && score<=79)
            C++;
        else if(score>=60 && score<=69)
            D++;
        else if(score>=0 && score<=59)
            F++;
        }
        I++;
    } // <- the while loop should end here 

   System.out.println("Total number of A's:"+ A);
   System.out.println("Total number of B's:"+ B);
   System.out.println("Total number of C's:"+ C);
   System.out.println("Total number of D's:"+ D);
   System.out.println("Total number of F's:"+ F);

}

Answer 2

您的代码中有两个问题：

您在System.out.println内有while
您不会减少学生，因此它总是会要求分数，这意味着它永远不会超出while循环。

这是完成的方式

    int A = 0, B = 0, C = 0, D = 0, F = 0, score, I, students;
    I = 1;
    Scanner input = new Scanner(System.in);
    System.out.println("How many students are in your class: ");
    students = input.nextInt();

    while (I <= students) {
        System.out.println("enter a score:");
        score = input.nextInt();


        if (score >= 90 && score <= 100)
            A++;
        else if (score >= 80 && score <= 89)
            B++;
        else if (score >= 70 && score <= 79)
            C++;
        else if (score >= 60 && score <= 69)
            D++;
        else if (score >= 0 && score <= 59)
            F++;

        students--;

    }
    System.out.println("Total number of A's:" + A);
    System.out.println("Total number of B's:" + B);
    System.out.println("Total number of C's:" + C);
    System.out.println("Total number of D's:" + D);
    System.out.println("Total number of F's:" + F);

我添加了students--，因为它会减少您得分的学生人数，因此当学生用完时，它将退出while循环

Answer 3

感觉在循环括号中放错了位置。将括号（while循环的右括号）放在f ++之后。希望这能解决您的问题。还有学生-应该在那里。

我建议您使用for循环，我发现它对于初学者来说要简单得多。

for( int i=0; i < students; i++) {
  //statements here  
}

Answer 4

您正在每个循环中打印所需的输出，因此请将打印语句放置在循环外部。另外，当前循环是无限的，因此在每个循环中增加 I 的值或减小学生的值。您的代码应类似于：

private slots:
     void zoomBarAct(int zoom);

Answer 5

尝试一下：

{ 
    int A=0,B=0,C=0,D=0,F=0, score;

    Scanner s = new Scanner(System.in);

    System.out.println("How many students are in your class: ");

    int numberOfStudents = s.nextInt();

    for (int i = 0 ; i < numberOfStudents ; i++) {
        System.out.println("enter score from 0 to 100 for student number " + (i + 1)  + " :");
        score =s.nextInt();

            if(score >= 90 && score <= 100)
                A++;
            else if(score>=80 && score<=89)
                B++;
            else if(score>=70 && score<=79)
                C++;
            else if(score>=60 && score<=69)
                D++;
            else if(score>=0 && score<=59)
                F++;

    }

       System.out.println("Total number of A's:"+ A);
       System.out.println("Total number of B's:"+ B);
       System.out.println("Total number of C's:"+ C);
       System.out.println("Total number of D's:"+ D);
       System.out.println("Total number of F's:"+ F);
}

如果陈述正确，我怎么能得到这个？

5 个答案: