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Thread: Help Calculating a tip

  1. #1
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    Default Help Calculating a tip

    Hello everyone! Having a bit of trouble with the math on this one. When I run the program it doesn't read the gratuity as a percentage, which is why it's showing up as a whole number. I need this program to basically output the tip amount by itself, and then the grand total. Of course allowing the user to input whatever the rate of gratuity is. Any help/advice is appreciated!

    package calculatingtip;
    import java.util.Scanner;
    public class CalculatingTip
    {
     
        public static void main(String[] args)
        {
            Scanner input=new Scanner(System.in);
            double billBeforeTip;
            double tipRate;
            double tipAmount;
            double grandTotal;
     
            System.out.println("Enter Bill Amount");
            billBeforeTip = input.nextDouble();
            System.out.println("Enter Rate of Gratuity");
            tipRate = input.nextDouble();
            System.out.println("The Amount before the tip is: " + billBeforeTip + 
                    " The Gratuity rate is " + tipRate + "%");
            tipAmount = billBeforeTip * tipRate;
            grandTotal = tipAmount + billBeforeTip;
            System.out.println("The Grand Total comes to " + grandTotal +
                    "The Gratuity is: " + tipAmount);
        }
    }


  2. #2
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    Default Re: Help Calculating a tip

    Well, think about this logically: how do you calculate a percentage?
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    Default Re: Help Calculating a tip

    Let me guess: Divide the smaller number by the bigger one and multiply by one hundred?

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    Default Re: Help Calculating a tip

    "15 percent" means literally, 15 / 100. 15 percent, or '%', of something is

    something * ( 15 / 100 )

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    Default Re: Help Calculating a tip

    I'm still having issues implementing this into my code. I see how I would need to get the number and divide it by 100, but I'm not sure which variables I need to include, and how the percentage can be chosen by the user. I appreciate the help so far.

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    Default Re: Help Calculating a tip

    The standard tip rate isn't 15%, it's 0.15 when you actually calculate. So you would want to update whichever variable represents the tip amount to reflect that.

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    Default Re: Help Calculating a tip

    Thanks for the help everyone, I got my code working great now! Just a quick question though. When the tip amount is displayed at the end of my new program, it shows up as $1.5 (When 15% is the tip amount). Is there a way to make it show up as $1.50? I am mostly inquiring about the aesthetics of the output, not necessarily the function. Thanks again!

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    Default Re: Help Calculating a tip

    Do a search on formatting java output

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    Default Re: Help Calculating a tip

    hanks for the help everyone, I got my code working great now! Just a quick question though. When the tip amount is displayed at the end of my new program, it shows up as $1.5 (When 15% is the tip amount). Is there a way to make it show up as $1.50? I am mostly inquiring about the aesthetics of the output, not necessarily the function.
    There's a function called printf used for formatting console output.

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    Default Re: Help Calculating a tip

    And yet another class called DecimalFormat.
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