java.lang.ArrayIndexOutOfBoundsException：3 while循环 [英] java.lang.ArrayIndexOutOfBoundsException: 3 in a while loop

问题描述

我已经得到这个例外，我不知道如何去修复它：

I've been getting this exception and I've no idea how to go about fixing it:

java.lang.ArrayIndexOutOfBoundsException: 3

在，而循环。这里是我的code：

in the while loop. Here's my code:

public class NameSearch {
    static String[] names = new String[3];

    void populateStringArray() {
        names[0] = "Ben";
        names[1] = "Thor";
        names[2] = "Zoe";
        names[3] = "Kate";
    }

    public static void main(String[] args) {
        String pName;
        int max = 4;
        int current = 1;
        boolean found = false;

        Scanner scan = new Scanner(System.in);
        System.out.println("What player are you looking for?");
        pName = scan.next();
        while (found == false && current <= max) {
            if (names[current] == pName) {
                found = true;
            } else {
                current = current + 1;
            }
        }
        if (found == true) {
            System.out.println("Yes, they have a top score");
        } else {
            System.out.println("No, they do not have a top score");
        }
    }
}

在code意在要求用户输入一个名称，它会检查，看看是否名字是阵列中（简言之）。

The code is meant to ask the user to input a name and it will check to see if the name is in the array (in a nutshell).

我的IDE（Eclipse中）说，错误在于行如果（名称[现行] == PNAME）{。

My IDE (Eclipse) says that the error lies in the line if (names[current] == pName){.

推荐答案

您的索引在循环的数组元素 1 和 4 （含）的，当你需要将它们编索引 0 和 3 （含）

You are indexing your array elements in the loop between 1 and 4 (inclusive), when you need to be indexing them between 0 and 3 (inclusive).

修改电流在 0 启动和最大是 3 ，你应该都不错。

Change current to start at 0, and max to be 3 and you should be all good.

有关或许是更好的选择，考虑把你的邮件列表的名字在 HashSet的键，不需要在所有迭代。例如。

For perhaps an even better alternative, consider putting your list of names in a HashSet and not needing to iterate at all. E.g.

Set<String> names = new HashSet<String>();
names.add("Ben");
names.add("Thor");
names.add("Zoe");
names.add("Kate");

if (names.contains(pName)) {
//...

如果姓名的顺序是非常重要的，那么你可以使用列表来代替，其中也有一个包含方法（只是不一般同样有效，在地图实施.. O（N） VS O（1）典型值）。如果名称列表中的数量比较少或性能不是一个问题，那也没什么关系无论哪种方式。

If the ordering of the names is important, then you could use a List instead, which also has a contains method (just not generally as efficient as that in a Map implementation.. O(n) vs O(1) typically). If the number of names in your list is small, or performance is not an issue, then it will not matter either way.

这篇关于java.lang.ArrayIndexOutOfBoundsException：3 while循环的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！