Java，减去双精度数据类型

我正在做一个简单的计算。在最后的if-else语句中，我不知道如何减去双重许可价格

它指向减法符号，给了我这个错误信息： 运算符-不能应用于java.lang.String，双精度

请帮忙。谢谢

您需要添加以修复优先级，否则，正如错误所示，您将不是从admissionPrice中减去，而是从以下字符串中减去：…:+admissionPrice

在admissionPrice-admissionPrice*0.15周围加上括号。现在，它将折扣15%后的admissionPrice连接到总价上，即：在尝试减法之前。

println语句中的+运算符优先，并将admissionPrice转换为字符串

---

把你的算术运算放在括号里。

你可以用around来避免这个admissionPrice-admissionPrice*0.15。试着把整个数字表达式用括号括起来：admissionPrice-admissionPrice*0.15我不明白这里的反对票，对我来说没有任何意义。

import java.text.*;
import java.util.Scanner;


class IMC {
    public static void main(String[] args) {

    int numEmployees = 0;
    double costPerAttendee = 0.00;
    int employeeDiscount;
    double admissionPrice = 0.00;

    Scanner keyboard = new Scanner (System.in);

    System.out.print("Enter amount of employees attending: ");
    numEmployees = keyboard.nextInt();

    System.out.print("Have any employees attended previously? \n For: YES=1 or NO=2"
                        );
    employeeDiscount = keyboard.nextInt();



    if (numEmployees == 1)  { admissionPrice = 695.00;


    } else if (numEmployees == 2 || numEmployees ==  3 ||numEmployees ==  4) { admissionPrice = 545.00;


    } else if (numEmployees >= 5 ||numEmployees >= 6 ||numEmployees >= 7 ||numEmployees >= 8){ admissionPrice = 480.00;


    }  else if (numEmployees >= 9)  { admissionPrice = 395.00;

    }

        System.out.print("The cost per attendee is: " + admissionPrice );


  if (employeeDiscount == 1){
        System.out.print("Total price after discount (15%) is : " + admissionPrice - (admissionPrice * 0.15) );

    } else if (employeeDiscount == 2) {
            System.out.print("No discount. Total price is still: " + admissionPrice);
    }   


    }
}

System.out.print("Total price after discount (15%) is : " + (admissionPrice - (admissionPrice * 0.15)));
                                                            ^                                        ^