数组索引越界异常？ [英] Array index out of bounds exception?

问题描述

此代码应返回数组中最长字符串的长度。我不知道如何做到这一点或修复此错误。我不明白该方法的工作部分。有什么建议/帮助吗？提前致谢。

   
  public   static   double 最长（字符串 [] A）{
  int  max =  0 ; 
  for （ int  i = 0; i< A.length; i ++）{
  if （A [i] .length（）< A [i ++] .length（））{
 max = A [i] .length （）; 
} 
  else  
 max = A [i ++] .length（）; 
} 
 返回 max; 
} 
 
  public   static   void  main（ String  [] args）{
  String  [ ] S2 = {  H， 嗨， 嘿嘿，  嘿！}; 
 System.out.println（最长（S2））; 
} 
} 
 
线程中的异常  main java.lang.ArrayIndexOutOfBoundsException： 4  
 at fixMyCode.longest（fixMyCode.java： 8 ）fixMyCode.main的
（fixMyCode.java： 15 ）

我尝试了什么：



我试过搞乱for语句本身，但我不知道是什么我正在做。

解决方案

尝试

  for （ int  i =  0 ; i< A.length   -   1  ; i ++）{
  if （A [i] .length（）< ; A [i +  1 ]。length（））{
 max = A [i] .length（）; 
} 
  else  
 max = A [i +  1 ] 。长度（）; 
} 

i ++ 与 i + 1不一样。

i ++ 修改 i 变量，而 i + 1 只计算增量但保持变量不变。

所以你的问题是你在循环中与循环变量进行交互。在某些时候，给定这些意外的增量，索引变量超出范围，导致您得到的错误消息。

请注意，因为您使用 i + 1 在循环中，你必须迭代，直到最后一个元素，但直到最后一个元素，以便索引永远不会超出范围。

< blockquote class =quote>

引用：

数组索引越界异常？

错误消息id因为i ++改变了值我和你在数组结束后结束。

引用：

这段代码应该返回的长度数组中最长的字符串。

你的算法是完全错误的，你没有通过比较数组的2个连续元素来获得最大长度。

你通过比较元素的长度与当前最大值来获得最大长度

This code is supposed to return the length of the longest string in an array. I'm not sure how to make it do that or fix this error. I don't understand the working parts of the method. Any suggestions/help? Thanks in advance.

   public static double longest(String[] A) {
     int max = 0;		
       for (int i=0; i<A.length; i++) {
            if (A[i].length() < A[i++].length()) {
                max = A[i].length();
	    }
            else
                max = A[i++].length();			
        }
        return max;
    }

    public static void main(String[] args) {
			String[] S2 = {"H", "Hi", "Hey", "Hey!"};
        System.out.println(longest(S2));
  }
}

Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 4
        at fixMyCode.longest(fixMyCode.java:8)
        at fixMyCode.main(fixMyCode.java:15)

What I have tried:

I've tried messing with the for statement itself, but I don't know what I'm doing.

解决方案

Try

for (int i = 0; i < A.length - 1; i++) {
   if (A[i].length() < A[i + 1].length()) {
      max = A[i].length();
   }
   else
      max = A[i + 1].length();			
}

i++ is not the same as i + 1.
i++ modifies the i variable, whereas i + 1 just computes the increment but leaves the variable intact.
So your problem is that your are interacting with the loop variable inside the loop. At some point, given these unexpected increments, the index variable goes out of scope, leading to the error message you get.
Note that, since you are using i + 1 in the loop, you have to iterate, not until the last element, but until the last but one, so that the indexing never goes out of scope.

Quote:

Array index out of bounds exception?

The error message id because i++ change the value of i and you endup after the end of array.

Quote:

This code is supposed to return the length of the longest string in an array.

Your algorithm is plain wrong, you don't get the maximum length by comparing 2 consecutive elements of an array.
You get max length by comparing length of an element with current max.

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