java - 收银机返回剩余金额加上二次付款的零钱

Question

我以为我的做法是正确的，但是当我尝试在“收银机”中拆分付款时，它在第二次和第一次付款上都返回了正确的找零，但在第二次付款上，它包含我放置的第三个 if 语句，并且它也给出了找零。

例如:

Price: $100.00
Sales tax = $6.00
Total amount due = $106.00
Payment = $50.00
Amount Remaining: $56.00
Payment $50.00
Amount Remaining: $6.00
Your Change Is: $44.00

这是有问题的代码段。如有任何帮助，我们将不胜感激。

 public void makePayment (double payment){


    if (payment < 0){
        System.out.println("Insufficient Funds. Please Use Another Method Of Payment");
    }

    if (payment < currentAmountDue ){
        currentAmountDue = currentAmountDue - payment;
        System.out.println("Amount Remaining: " + fmt.format(currentAmountDue));
        dailySales = currentAmountDue + dailySales;
    }

    if (payment > currentAmountDue){
        dailySales = dailySales + currentAmountDue;
        currentAmountDue = payment - currentAmountDue;
        System.out.println("Your Change Is: " + fmt.format(currentAmountDue));
        numberOfCustomers = numberOfCustomers + 1;
        dailySales = currentAmountDue + dailySales;
    }

    if (payment == currentAmountDue){
        dailySales = dailySales + currentAmountDue;
        numberOfCustomers = numberOfCustomers + 1;
        currentAmountDue = 0;
        System.out.println("Thank you for your money!");
    }
}

Answer 1

如果您查看第二次付款的代码，很容易发现这一点。

输入后currentAmountDue=56和 payment=50，所以

if (payment < currentAmountDue )

这是真的，你也这么做

 currentAmountDue = currentAmountDue - payment;

现在 currentAmountDue=6 并且仍然 payment=50 并且执行下一个 if 语句:

if (payment > currentAmountDue){

其计算结果也为true。

您只想执行一个 if 分支，因此最好将除第一个之外的所有 if 分支更改为 else if。