Java车辆租赁系统数组无法打印首个元素 仅输出最后一次输入值

• 赋值逻辑错误：处理用户第i次输入的车型时，你嵌套了遍历整个vehicleRentedArry的j循环，会把数组所有位置的元素都覆盖为当前输入的车型。比如你输入2辆车，第一次输入Car时，数组下标0、1都会被设为Car；第二次输入Trailer时，数组下标0、1又会被全部覆盖为Trailer，最终数组中所有元素都是最后一次输入的车型，所以打印时全是Trailer。
• 打印逻辑不符合要求：当前打印每次都调用println自动换行，且没有做首行和后续行的格式区分，无法实现首个车型和标题同行的效果。
• 附加问题：税费计算逻辑错误，你在循环累加日租金时每次都乘1.06，相当于重复计税，正确逻辑应该是总租金累加完成后统一乘以税率。

1. 修复车型数组赋值逻辑 #

删掉内层的j循环，直接给对应下标的vehicleRentedArry[i]赋值即可，修改后代码：

for(int i = 0; i < vehicleTypes.length; i++) {
    System.out.println("What vehicle type would you like? Motorbike, trailer, or car?: ");
    vehicleType = ReadStringFromUser();
    if((vehicleType.equalsIgnoreCase("Motorbike")) || (vehicleType.equalsIgnoreCase("Trailer")) || (vehicleType.equalsIgnoreCase("Car"))) {
        vehicleTypes[i] = vehicleType;
        // 删掉内层j循环，直接给i下标赋值
        if(vehicleType.equalsIgnoreCase("Motorbike")) {
            CMotorbike motorbikeOption = new CMotorbike();
            motorbikeOption.SetMethods("Handle Bars", 35, 2);
            vehicleRentedArry[i] = motorbikeOption;
        }else if(vehicleType.equalsIgnoreCase("car")) {
            CCar carOption = new CCar();
            carOption.SetMethods("Steering Wheel", 25, 4);
            vehicleRentedArry[i] = carOption;
        }else if(vehicleType.equalsIgnoreCase("Trailer")) {
            CTrailer trailerOption = new CTrailer();
            trailerOption.SetMethods("Use Another Vehicle", 0, 6);
            vehicleRentedArry[i] = trailerOption;
        }
    }
}

2. 修复税费计算逻辑 #

把税率计算移到循环外：

//Calculate the rates
dailyRates = CalculateDailyRates(vehicleTypes, numOfVehicles, numOfDays);

//Check if rates appear correctly
for(int k = 0; k < dailyRates.length; k++) {
    totalRentalSale += dailyRates[k];
}
// 总金额累加完成后统一计税
totalRentalSale = totalRentalSale *1.06f;

3. 修复打印格式逻辑 #

判断下标是否为0，首行不换行，后续行补缩进后换行：

//Printing the outputs:
System.out.println("** Order Confirmation **");
System.out.printf("----------------------------------------------------------------------\n");
System.out.printf("Customer Name: \t\t\t\t%s %s\n", strFirstName, strLastName);
System.out.printf("Phone Number: \t\t\t\t%s\n", strPhoneNumber);
System.out.printf("Email: \t\t\t\t\t%s\n", strEmail);
System.out.printf("----------------------------------------------------------------------\n");
System.out.println("** Details about Rental **");
System.out.printf("----------------------------------------------------------------------\n");
System.out.printf("Type of Vehicle: \t\t\t");
for(int intIndex = 0; intIndex < vehicleRentedArry.length; intIndex++) {
    String vehicleType = vehicleRentedArry[intIndex].getVehicleType();
    if(intIndex == 0) {
        // 首辆车和标题同行
        System.out.println(vehicleType);
    } else {
        // 后续车辆前面补对应缩进，再打印
        System.out.printf("\t\t\t\t\t%s\n", vehicleType);
    }
}

内容的提问来源于stack exchange，提问作者Brittney P