Question

在我的java类中，我们开始编写方法，而不是将所有代码放在main方法中。问题集中的一个问题是“编写一个方法，询问用户他们已经采取的课程数量 n 。然后该方法将要求 n

 import java.util.*;

    public class MethodPracticeSet2 
    {public static int average()
    {
    //Create new Scanner object
    Scanner sc=new Scanner(System.in);

    //Create divisor variable
    int divisor=0;

    //Ask user for their course
    System.out.println("How many courses are you currently in?");
    int course =sc.nextInt();
    for (int i=0; i<course; i++)
    {
        System.out.println("What are your grades for those courses?");
        int grades[]= new int[i];
        grades[i]=sc.nextInt();
        divisor= divisor+i;
    }
    System.out.println("Your average for these courses is "+divisor/course);
    return average();
    }

    public static void main(String[] args) 
    {
        int output=average();
        System.out.println(output);
    }

    }

输出询问用户所在的课程数量，然后询问成绩，然后输出以下内容：

Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 0 at MethodPracticeSet2.average(MethodPracticeSet2.java:24) at MethodPracticeSet2.main(MethodPracticeSet2.java:33)

任何帮助都会很棒！

Answer 1

首先，您需要在循环之前声明您的数组。目前，您在循环的每次迭代中创建一个新数组，这显然不是您想要做的;这也是您获得ArrayIndexOutOfBoundsException的原因，原因是当您使用i 0实例化数组时，您试图存储数字进入空数组因此异常。

这是你应该如何声明数组：

int grades[] = new int[course]; for (int i = 0; i < grades.length; i++) { System.out.println("What are your grades for those courses?"); grades[i] = sc.nextInt(); divisor += 1; }

然后返回这些成绩的平均值，你可以这样做：

int totalGrades = 0; for(int grade : grades){ totalGrades += grade; } System.out.println("Your average for these courses is "+totalGrades / divisor); return totalGrades / divisor;

Answer 2

试试这个：

public class MethodPracticeSet2 {
public static int average() {
    // Create new Scanner object
    Scanner sc = new Scanner(System.in);

    // Create divisor variable
    int divisor = 0;

    // Ask user for their course
    System.out.println("How many courses are you currently in?");
    int course = sc.nextInt();
    System.out.println("What are your grades for those courses?");
    int sum = 0;
    for (int i = 0; i < course; i++) {
        sum += sc.nextInt();
    }
    System.out.println("Your average for these courses is " + (float) sum / course);
    return average();
}

public static void main(String[] args) {
    int output = average();
    System.out.println(output);
}

}

需要从一组用户的成绩中获得平均值

2 个答案: