越界異常乘數組

Question

據我所知，這個程序是正確完成的。但是，鑑於它似乎沒有例外。我將創建2個長度爲x的數組（用戶輸入），用戶將輸入這些元素。完成。接下來，將每個元素乘以另一個數組中的相應元素並添加總和。

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

精確的錯誤是：異常在線程 「主」 java.lang.ArrayIndexOutOfBoundsException：

我已經做了許多不同的循環，下面的最後一個循環，我有額外的空間來識別是我認爲最接近正確，但不是。我非常感謝一些建議，提前謝謝。

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

，當你訪問德陣列

更改<=符號<。例如：

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

記住，如果length是4，你可以訪問元素：

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

array[4]不存在，導致了IndexOutOfBounds例外。

編輯

奇怪輸出[I@756a7c99（例如）是因爲你打印一個數組：

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

相反，你可能要打印該數組的元素：

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

編輯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();