Question

我刚刚开始使用java，但我不太清楚错误。我认为它与我的字符串数组有关。当我运行它时，在第一次输入后，我收到错误消息：

Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 4
    at CurveBreaker.main(CurveBreaker.java:13)

非常感谢任何帮助。

import java.util.Scanner;

public class CurveBreaker {
    public static void main(String[]args){
        Scanner input = new Scanner(System.in);

        System.out.println("Enter the number of students.");
        int i = input.nextInt();
        int[] StudentGrades = new int[i];

        String[] Students = new String[i];

        System.out.println("Enter the name of the student.");
        Students [i] = input.next();
        System.out.println("Enter the student's score.");
        StudentGrades[i] = input.nextInt();
        String Best = Students [i];
        int BestNumb = StudentGrades [i];
        i--;
        for(i=i; i>0;i--){
            System.out.println("Enter the name of the student.");
            Students [i] = input.next();
            System.out.println("Enter the student's score.");
            StudentGrades[i] = input.nextInt();
            if(StudentGrades[i] > BestNumb){
                BestNumb = StudentGrades[i];
                Best = Students [i];
            }

        }

        System.out.println("The highest score was " + BestNumb + " which was      achieved by " + Best);
    }
}

Answer 1

Java数组具有从0到i-1的索引。您正尝试将1用于i

Answer 2

因此，您提示用户输入元素数量......

System.out.println("Enter the number of students.");
int i = input.nextInt();
int[] StudentGrades = new int[i];

String[] Students = new String[i];

好的，那很酷，但是你呢......

System.out.println("Enter the name of the student.");
Students[i] = input.toString();

现在，这有两个问题，一个，input.toString()不会要求用户输入，它只是分配toString的结果到元素i

的Students数组

两个，i仍然等于用户输入的值。例如，如果他们输入5，则您尝试为元素5分配一个值，该值不存在，因为Java数组基于0（0-4 }）

更好的解决方案可能是做一些像......

System.out.println("Enter the number of students.");
int i = input.nextInt();
input.nextLine(); // This is important, it clears the carriage return from the buffer
int[] StudentGrades = new int[i];
String[] Students = new String[i];

for (int index = 0; index < i; index++) {
    System.out.println("Enter the name of the student.");
    Students[i] = input.nextLine();
    System.out.println("Enter the student's score.");
    StudentGrades[i] = input.nextInt();
    input.nextLine();
    // calculate stuff here...
}

但是，你似乎想要以相反的顺序输入它们，好吧，使用像......这样的东西。

for (int index = i - 1; index >= 0; index--) {

，而不是...

您可能还想查看The Arrays tutorial

数组和字符串的麻烦

2 个答案: