小数点以下2桁になるように、二重の「amt」をドル金額println( "$"+ドル+"。"+セント)としてフォーマットする必要があります。
そうするための最良の方法は何ですか?
if (payOrCharge <= 1)
{
System.out.println("Please enter the payment amount:");
double amt = keyboard.nextDouble();
cOne.makePayment(amt);
System.out.println("-------------------------------");
System.out.println("The original balance is " + cardBalance + ".");
System.out.println("You made a payment in the amount of " + amt + ".");
System.out.println("The new balance is " + (cardBalance - amt) + ".");
}
else if (payOrCharge >= 2)
{
System.out.println("Please enter the charged amount:");
double amt = keyboard.nextDouble();
cOne.addCharge(amt);
System.out.println("-------------------------------");
System.out.println("The original balance is $" + cardBalance + ".");
System.out.println("You added a charge in the amount of " + amt + ".");
System.out.println("The new balance is " + (cardBalance + amt) + ".");
}