使用&& / ||和带有次要参数的用户输入进行while循环

Question

I'm trying to enter a condition where the user gets caught in a while loop until they enter a decimal between .00 and .025 , no higher or lower.

System.out.println("Enter the interest rate you would like, preferablly between .00 and .25");
while ((interestRate = keyboard.nextDouble()) < 0.00 || ((interestRate = keyboard.nextDouble()) < 0.25))
{
    System.out.println("Just a number between .00 and .25, no more, no less!");
}
System.out.println("Testing for break");

I'm unable to get the accursed thing to run both ways properly, but always run into a blank.

Answer 1

You're calling keyboard.nextDouble() twice inside the condition (although only the first will be evaluated if the (first!) input is in fact negative). Probably, don't call it at all inside the condition:

while(true) {
  interestRate=keyboard.nextDouble();
  if(interestRate>=0 && interestRate<=0.25) break;
  System.out.println("...");
}

(The conditional for 0.25 was also backwards in your version.)

Answer 2

You're calling nextDouble() twice, and your second condition is reversed. Try this:

while ((interestRate = keyboard.nextDouble()) < 0.00 || interestRate > 0.25)