越界异常乘数组

Question

据我所知，这个程序是正确完成的。但是，鉴于它似乎没有例外。我将创建2个长度为x的数组（用户输入），用户将输入这些元素。完成。接下来，将每个元素乘以另一个数组中的相应元素并添加总和。

例，ARRAY1 [0] *数组2 [0] + ARRAY1 [1] *数组2 [1] ...

精确的错误是：异常在线程 “主” java.lang.ArrayIndexOutOfBoundsException：

我已经做了许多不同的循环，下面的最后一个循环，我有额外的空间来识别是我认为最接近正确，但不是。我非常感谢一些建议，提前谢谢。

System.out.println("This program will multiply 2 one dimension arrays of any length. \n The length and contents of the array is entered from the keyboard."); 
    System.out.println("Enther the data for the first array. "); 

    System.out.println("Enther the length of the array (remember arrays being counting at 0, not 1:"); 

    int a = 0; 
    Scanner keyboard = new Scanner(System.in); 
    a = keyboard.nextInt(); 
    int[] firstArrayLength = new int[a]; 
    System.out.println("Enter the elements of the first array(remember arrays begin counting at 0, not 1"); 
    double arrayElements = 0; 
    for (int elements = 0; elements <= firstArrayLength.length; elements++) { 

     arrayElements = keyboard.nextInt(); 
    } 

    System.out.println("Enter the data for the second array. "); 
    System.out.println("Enter the elements of the second array(remember arrays begin counting at 0, not 1"); 
    int[] secondArrayLength = new int[a]; 

    double secondArrayElements = 0; 
    for (int elements = 0; elements <= secondArrayLength.length; elements++) { 

     secondArrayElements = keyboard.nextInt(); 
    } 
    double [] thirdArray = new double [a]; 





    for (int i =0; i <=firstArrayLength.length; i++) 
     { 
     thirdArray[a] = firstArrayLength[i]*secondArrayLength[i]; 
     } 
    System.out.println(thirdArray); 
     } 

Answer 1

，当你访问德阵列

更改<=符号<。例如：

for (int elements = 0; elements < firstArrayLength.length; elements++) 
... 

记住，如果length是4，你可以访问元素：

array[0], array[1], array[2], array[3] // 4 elements 

array[4]不存在，导致了IndexOutOfBounds例外。

编辑

奇怪输出[I@756a7c99（例如）是因为你打印一个数组：

int a[] = new int[4]; 
System.out.println(a); 

相反，你可能要打印该数组的元素：

int a[] = new int[4]; 
for (int i = 0; i < 4; i++) { 
    System.out.println(a[i]); 
} 

编辑2

public static void main(String[] args) { 
    System.out 
      .println("This program will multiply 2 one dimension arrays of any length. \n The length and contents of the array is entered from the keyboard."); 
    System.out.println("Enther the data for the first array. "); 

    System.out 
      .println("Enther the length of the array (remember arrays being counting at 0, not 1:"); 

    int a = 0; 
    Scanner keyboard = new Scanner(System.in); 
    a = keyboard.nextInt(); 
    int[] firstArray = new int[a]; 
    System.out 
      .println("Enter the elements of the first array(remember arrays begin counting at 0, not 1"); 
    for (int elements = 0; elements < firstArray.length; elements++) { 

     firstArray[elements] = keyboard.nextInt(); 
    } 

    System.out.println("Enter the data for the second array. "); 
    System.out 
      .println("Enter the elements of the second array(remember arrays begin counting at 0, not 1"); 
    int[] secondArray = new int[a]; 

    for (int elements = 0; elements < secondArray.length; elements++) { 

     secondArray[elements] = keyboard.nextInt(); 
    } 
    double[] thirdArray = new double[a]; 

    for (int i = 0; i < firstArray.length; i++) { 
     thirdArray[i] = firstArray[i]*secondArray[i]; 
    } 

    for (int i = 0; i < thirdArray.length; i++) 
     System.out.println(thirdArray[i]); 
} 

Answer 2

elements <= firstArrayLength.length ==>elements < firstArrayLength.length

arrayElements = keyboard.nextInt(); == >>firstArrayLength[elements] = keyboard.nextInt();

secondArrayElements = keyboard.nextInt(); == >>secondArrayLength[elements] = keyboard.nextInt();