我的条件不起作用，我是初学者

Question

double a = 10;// the 10 dollars to spend
double b = 0;// the cost of he food
double c;// final total
double d;// amount of sandwiches
c = a-b;
String Order;
Scanner sc = new Scanner(System.in);

And here is what i'm trying to do my objective is to get the number of sandwiches and multiply it; while the number is 2 or lower she says one thing 3 or higher another. The problem is it's asking me to initialize the variable to 0 but obviously d*0 is still zero.

System.out.println("That'll be 1.06 how many would you like?");
b = 1.06*d;
d = sc.nextDouble();
System.out.println(d <= 2 ?"Ok! Coming right up Sir!":"...Ok.... she     probably thinks you're a fatso now.");
System.out.println("She hands you back "+(a-b)+" as your change");
break;

Answer 1

The problem is here:

System.out.println("That'll be 1.06 how many would you like?");
b = 1.06*d;
d = sc.nextDouble();

You haven't initialized d , so when you do your multiplication you are multiplying nothing. You need to load the scanner's value into d before you multiply b .

System.out.println("That'll be 1.06 how many would you like?");
d = sc.nextDouble();
b = 1.06*d;

Answer 2

Swap the order of your assignments.

b = 1.06*d; // <-- what's d?
d = sc.nextDouble();

like

d = sc.nextDouble();
b = 1.06 * d;

Also, you should pick more meaningful variable names.