java - ArrayIndexOutOfBoundsException，但元素打印正常

Question

此错误消息的含义是什么:

Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 1 at Program.main(Program.java:123)

这是第 123 行:

System.out.println(tempHolder[1]);

也就是说没有数组元素1？然而，这是一个循环，并且该位置的所有 100 个元素都打印得很好。代码如下:

数组 splitResult 有 100 个元素。

    int counter = 0;
    for (String s: splitResult){ 
      counter++; 
      counterForRegex = String.valueOf(counter);  
      stringRegex = "(\\s*)?" + counterForRegex + "(\\s*)?"; 
      patternCounter = Pattern.compile(stringRegex); 
      tempHolder = patternCounter.split(s, 2);  // This takes each of the 100 elements and separates it into 0) before the number, and 1) after the number, putting each element in array tempHolder.
      splitResult[counter-1] = tempHolder[0]; 
      System.out.println(tempHolder[1]); // These all print fine.
    }

Answer 1

tempHolder = patternCounter.split(s, 2);//当未找到数字时，拆分结果仅返回输入。

tempHolder.length 将为 1 ，在这种情况下，尝试访问 tempHolder[1] 时会抛出 java.lang.ArrayIndexOutOfBoundsException。

 tempHolder = patternCounter.split(s, 2); 
  if(tempHolder.length>=2){//check the length of tempHolder
     splitResult[counter-1] = tempHolder[0]; 
     System.out.println(tempHolder[1]); // These all print fine.
  }