java - 数组越界>

Question

我需要创建一个程序来计算您将收到的变化，但它说:

线程“main”中的异常java.lang.ArrayIndexOutOfBoundsException:索引9 长度 5 出界 在 Main.main(Main.java:34)

我对在 Java 中使用数组还很陌生，所以任何指针都会有帮助

import java.math.*;

public class Main {

    static int changeTotal, penny, nickel, dime, quarter, dollarBill,  fiveBill, tenBill, twentyBill, fiftyBill, hundredBill;
    static double payed, price;

    public static void main(String args[]) {

        Scanner myScan = new Scanner(System.in);

        System.out.println("Enter cost of item");
        price = myScan.nextDouble();
        System.out.println("Enter money given");
        payed = myScan.nextDouble();

        int priceInt = (int) (price * 100);
        int payedInt = (int) (payed * 100);

        penny = 1;
        nickel = 5;
        dime = 10;
        quarter = 25;
        dollarBill = 100;

        int[] currencyArray = {penny, nickel, dime, quarter, dollarBill};
        int[] changeCount = {0, 0, 0, 0, 0}; 
        if(payed > price) {
        changeTotal = payedInt - priceInt;
        }

        for(int i = 9; i >= 0; i--) {
          int remainder = (changeTotal % currencyArray[i]);
            if(remainder < changeTotal) { 
                changeCount[i] = (changeTotal - remainder) / currencyArray[i]; 
            changeTotal = remainder;
            }
        }

        System.out.println(payed - price);
        System.out.println("Ones: " + changeCount[4]);
        System.out.println("Quarters: " + changeCount[3]);
        System.out.println("Dimes: " + changeCount[2]);
        System.out.println("Nickels: " + changeCount[1]);
        System.out.println("Pennies: " + changeCount[0]);
    }
}

Answer 1

为了补充之前的答案，我建议使用对数组长度的引用，而不是硬连接该值。处理这样的情况可能是一个不错的做法，在这种情况下，您使用 for 循环来迭代数组，因为从那时起，如果数组将来由于某种原因发生变化，您不必跟踪硬编码值来调整它。例如，类似 for(int i =currencyArray.length - 1; i >= 0; i--) 的内容。