How can I make a user input 20 be read by the program as 20% or 0.20

Question

This is the part where I ask the user to input the following.

Enter the item name: Shirt

Original price of the item: 700

Marked-up Percentage: 20

Sales Tax Rate: 7

Output:

Item to be sold : Shirt
Original price of the item: 700.00
Price after mark-up: 840.00
Sales tax: 58.80
Final price of item: 898.80

so my question is how can I make that 20 and 7 input be read by the program as percentages.

    import java.util.*;
    import javax.swing.*;

    public class lab3 {
    public static void main(String[] args) {
    JOptionPane jo=new JOptionPane();
    String item=jo.showInputDialog("Item to be sold: ");
    double Oprice=Double.parseDouble(
            jo.showInputDialog("Original price of the item: "));
    double mup=Double.parseDouble(
            jo.showInputDialog("Marked-up percentage: "));   
    double str=Double.parseDouble(
            jo.showInputDialog("Sales Tax Rate: "));


    double pamu=(Oprice*mup)+Oprice;
    double ST=pamu*str;
    double result=pamu+ST;

    String hold= "\n| Item to be sold \t: "+item+"\t |"
                +"\n| Original price of the item \t: "+Oprice+"\t |"
                +"\n| Price after mark-up \t: "+pamu+"\t |"
                +"\n| Sales Tax \t: "+ST+"\t |"
                +"\n| Final price of the item \t: "+result+"\t |";
    jo.showMessageDialog(null, new JTextArea(hold));
    }
    }

That is my actual code. sorry if its messy. like I said still new to this

Hint: what happens if you divide by 100? (Making sure you're performing floating point arithmetic...) — Jon Skeet, Jul 03 '17 at 08:10
don't use floats or doubles though https://stackoverflow.com/questions/3730019/why-not-use-double-or-float-to-represent-currency — Tschallacka, Jul 03 '17 at 08:12
I really don't know how to add my actual code.. I'm still new to this. sorry — john felix, Jul 03 '17 at 08:29
I do not understand the question, what exactly is going wrong? I mean 700 + 20% = 840, as already being calculated/output by the code - same for rest of calculations. — user85421, Jul 03 '17 at 08:37
@johnfelix there is a "?" when entering/editing question for help which also has a link to [advanced help](https://stackoverflow.com/editing-help)... and **thank you** for answering my question [:-( — user85421, Jul 03 '17 at 08:50
The output does not match the code - why have you removed part of the code??? Accepting a non-working answer ?!?!!!! are you trying to get reputation ?? — user85421, Jul 03 '17 at 09:11

score 0 · Answer 1 · answered Jul 03 '17 at 08:23

0

Let's use Scanner for reading from user:

Scanner sc = new Scanner(System.in);
double percentage = 0.01 * sc.nextInt();

will do the trick.

answered Jul 03 '17 at 08:23

xenteros

15,586
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score -2 · Answer 2 · edited Jul 03 '17 at 09:25

-2

double pamu = (Oprice*(mup/100)) + Oprice; // enter code here
double ST = pamu*(str/100) ;
double result = pamu+ST ;

I think this should work.

edited Jul 03 '17 at 09:25

user85421

28,957
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answered Jul 03 '17 at 09:00

Akshay

1
2

Arvind Sasikumar · Accepted Answer · 2017-07-03T09:08:01.483

-3

Scanner keyboard = new Scanner(System.in);
System.out.println("Enter item name:");
String item;
keyboard.nextLine();
System.out.println("Original Price of item:");
double originalPrice;
keyboard.nextDouble();
System.out.println("Marked up percentage:");
double markedUpPercentage;
keyboard.nextDouble();
markedUpPercentage = markedUpPercentage/100; //this is what you want
System.out.println("Sales tax rate:");
double salesTaxRate;
keyboard.nextDouble();
salesTaxRate = salesTaxRate/100; //same thing here

//now output
System.out.println("Item to be sold: " + item);
System.out.println("Original price of the item: " + originalPrice);
System.out.println("Price after mark up: " + (originalPrice + originalPrice * markedUpPrice));
//similarly, do for sales tax

edited Jul 03 '17 at 09:08

answered Jul 03 '17 at 08:18

Arvind Sasikumar

482
3
15

My bad, didn't notice that. There was no code in the question itself so I assumed wrong. – Arvind Sasikumar Jul 03 '17 at 08:25
@johnfelix just copy paste it into the editor. Leave 4 spaces before you paste for the editor to understand what you are pasting is code. – Arvind Sasikumar Jul 03 '17 at 08:29
1

does that really work? compile? at least this is **not Java**! e.g. `nextLine` does not take any argument, neither does `nextDouble`!! and Java is pass-by-value, I expected something like `item = keyboard.nextLine()`... and since you already toke time to edit the answer, why not delete the "Since you haven't specified..." part at all? – user85421 Jul 03 '17 at 09:01

How can I make a user input 20 be read by the program as 20% or 0.20

3 Answers3