如何在 while 循环中将所有双打加在一起，java

Question

while (read.hasNext()) {

String roomType = read.nextLine();
int rooms = read.nextInt();
double price = read.nextDouble();
double roomIncome = (double) (rooms*price);
double tax = (double) (price*rooms*defaultTax);
double totalIncome = roomIncome;
roomIncome++; 
read.skip("\s+");      



        
System.out.println("Room type: " + roomType + " | No. of rooms: " + rooms + " | Room price: " + price + " | income: " + roomIncome + " | tax: " + tax);

System.out.println("The total room income is: " + totalIncome);

我需要将所有 roomIncome 加在一起得到 totalIncome 输出。目前我的输出是：

Room type: Single | No. of rooms: 5 | Room price: 23.5 | income: 118.5 | tax: 23.5
The total room income is: 117.5
Room type: Double | No. of rooms: 3 | Room price: 27.5 | income: 83.5 | tax: 16.5
The total room income is: 82.5
Room type: Suite | No. of rooms: 2 | Room price: 50.0 | income: 101.0 | tax: 20.0
The total room income is: 100.0

我的预期输出应该是所有 roomIncome 加在一起的总和。所以在这种情况下，它应该加起来为 300。相反，它向 roomIncome 加了 1，并给了我 100

的输出

Answer 1

如果要打印所有房型的总收入，需要在循环外维护变量，在循环内不断加值，如下：

double allRoomsTotalIncome = 0.0;

while (read.hasNext()) {

  String roomType = read.nextLine();
  int rooms = read.nextInt();
  double price = read.nextDouble();
  double roomIncome = (double) (rooms*price);
  double tax = (double) (price*rooms*defaultTax);
  double totalIncome = roomIncome;
  allRoomsTotalIncome = allRoomsTotalIncome + totalIncome;
  roomIncome++; 
  read.skip("\s+");      
        
  System.out.println("Room type: " + roomType + " | No. of rooms: " + rooms + " | Room price: " + price + " | income: " + roomIncome + " | tax: " + tax);
}



System.out.println("The total room income is: " + allRoomsTotalIncome);

如何在 while 循环中将所有双打加在一起，java

how to add together all doubles in a while loop, java

java

while-loop

double

add