java - 错误 : ArrayOutOfBounds. 如何解决？

Question

这个问题在这里已经有了答案:





How can I avoid ArrayIndexOutOfBoundsException or IndexOutOfBoundsException? [duplicate]

(2 个回答)


6年前关闭。




我已经编写了这个程序，但在编译时遇到了逻辑错误。获取 index.arrayOutOfBounds？

我的输入是 1, 2, 6, 10对于产品的选择和一致的输出应该是

Total items ordered: 3
Price of items ordered: $747.00
Sales Tax: $48.55
Total amount due: $795.55

我的 for 循环条件或计算中是否存在错误，或者导致此输出的数组是否存在错误？

import java.util.Scanner;
public class GrapefruitOrderingArray {

//Declare Constants 
public static final int SIZE = 100;
public static final int[] itemPrices = {49,299,329,399,199,1299,1199,999,599};  

public static void main(String[] args) {
// Declare Variables
    Scanner input = new Scanner (System.in);                                    
    String CustomerName;                                                       
    int[] naNumber = new int [SIZE];                                            
    int nProducts = 0;                                                        
    double nTotal = 0;                                                          
    double dFinalPrice = 0.0;                                                   
    int nCount = 0;                                                             

    //Declare Constants 
    final int SENTINEL = 10;   
    final double SALES_TAX = 0.065;

    //Prompt user to enter name
    System.out.println("Please enter your name: ");

    //Enter user name
    CustomerName = input.nextLine();

    System.out.println("");

    //Begin Product Listing Declarations with respect to array above
    System.out.println("GRAPEFRUIT PRODUCT:");
    System.out.println("1. gPod shuffle $" + itemPrices[0]);
    System.out.println("2. gPod Touch   $" + itemPrices[1]);
    System.out.println("3. gPad Mini    $" + itemPrices[2]);
    System.out.println("4. gPad 2       $" + itemPrices[3]);
    System.out.println("5. gPhone       $" + itemPrices[4]);
    System.out.println("6. gMac         $" + itemPrices[5]);
    System.out.println("7. MacNovel Pro $" + itemPrices[6]);
    System.out.println("8. MacNovel Air $" + itemPrices[7]);
    System.out.println("9. MiniMac      $" + itemPrices[8]);
    System.out.println("10. Complete my order");

    //Keep reading until the input is terminated by sentinel
    System.out.println("\nPlease select an item from the menu above: ");

    //Read number entered by the user
    naNumber[nCount] = input.nextInt();

    //Begin while-loop statement
    while (naNumber[nCount] != SENTINEL) {

    System.out.println("\nPlease select another item from the menu above: ");

    nCount++;

    //Read number entered by the user
    naNumber[nCount] = input.nextInt();
 }  

    System.out.println("Thank you for ordering with Grapefruit Company, " + CustomerName);
        //Call final price calculation
        dFinalPrice = calculateTotalPrice(naNumber,itemPrices,nTotal);

            //Print blank line to screen
            System.out.println("");

            //Total amount of product ordered
            System.out.println("Total items ordered: " + nCount );

            //Total price of items ordered
            System.out.println("Price of items ordered: $" + dFinalPrice );

            //Sales tax associated with the purchase
            System.out.println("Sales tax: $" + SALES_TAX * dFinalPrice );

            //Total amount due by the customer to Grapefruit Co. 
            System.out.println("Total amount due: $" + (SALES_TAX * dFinalPrice + dFinalPrice ));
    } //End main method

 private static double calculateTotalPrice(int[] naNumber, int[] itemPrices) {

  double total = 0;

  //Calculate entered items
  for(int i = 0; i < naNumber.length; i++){
   if(naNumber[i] != 0) {
   total += itemPrices[naNumber[i] - 1];
  }
}

  return total;
  }
} //end class calculateTotalPriceOfItemsOrdered

Answer 1

你的问题是因为在你的循环结束后你有 naNumber[nCount] == 10;然后在 calculateTotalPrice您正在尝试访问 total += itemPrices[9];这是超出范围的

快速解决方案:在您的 while 之后添加 naNumber[nCount] = 0;
但是您必须考虑如果用户输入了 100 多个产品，您的应用程序会做什么？