Java Variable Error

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August 20th, 2012, 08:09 AM

Connall

Registered User

Join Date: Aug 2012

Posts: 2

Time spent in forums: 20 m 37 sec
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Java Variable Error

Hey there, so I'm 16 and decided I wanted to teach myself Java after some success with other languages, I picked up a book to help me get on my way. While doing one of the exercises I came across a problem and made sure I had done the code correctly in the book, it appears I have but an error is still popping up.

Here's the code:

Code:

package ticketpricewithdiscount;

import java.util.Scanner;

public class TicketPriceWithDiscount {

    public static void main(String[] args) {
        Scanner myScanner = new Scanner(System.in);
        int age;
        double price;
        char reply;
        boolean isKid, isSenior, hasCoupon, hasNoCoupon;
        
        System.out.print("How old are you? ");
        age = myScanner.nextInt();
        
        System.out.print("Have a coupon? (Y/N) ");
        reply = myScanner.findInLine(".").charAt(0);
        
        isKid = age < 12;
        isSenior = age >=65;
        hasCoupon = reply =='Y' || reply == 'y';
        hasNoCoupon = reply =='N' || reply == 'n';
        
        if (!isKid && !isSenior) {
            price = 9.25;
        }
        
        if (isKid || isSenior) {
            price = 5.25;
        }
        
        if (hasCoupon) {
            price = 2.00;
        }
        
        if (!hasCoupon && !hasNoCoupon) {
            System.out.println("Huh?");
        }
        
          System.out.print("Please pay $");
          System.out.print(price);
          System.out.print(". ");
          System.out.println("Enjoy the show!");
        
                
    }
}

Now the error comes up at the

"System.out.print(price)" as price has a red line underneath it and the editor's reasoning to do this was:

"Initialize Variable price"

I thought I had already done that personally. Anyway, whatever help I could get is appreciated since I don't want to move on in case this pops up further down the road.

(I also apologise for what is probably stupidity.)

EDIT:

When I try to run it this comes up

Exception in thread "main" java.lang.NullPointerException
at ticketpricewithdiscount.TicketPriceWithDiscount.main(TicketPriceWithDiscount.java:18)

August 20th, 2012, 09:11 AM

MrFujin

Lord of the Dance

Join Date: Oct 2003

Posts: 3,130

Time spent in forums: 2 Months 2 Weeks 23 h 46 m 38 sec
Reputation Power: 1736

price is only assigned in if-block. You should give it a default value:

Code:

double price = 0.0;

Regarding NPE at line 18, you can use next() instead of findInLine():

Code:

reply = myScanner.next().charAt(0);

August 20th, 2012, 09:59 AM

Connall

Registered User

Join Date: Aug 2012

Posts: 2

Time spent in forums: 20 m 37 sec
Reputation Power: 0

Quote:

Originally Posted by MrFujin

price is only assigned in if-block. You should give it a default value:

Code:

double price = 0.0;

Regarding NPE at line 18, you can use next() instead of findInLine():

Code:

reply = myScanner.next().charAt(0);

Huh never thought of that. Wonder why my book doesn't mention it. Might be because it's from 2005 or something. Will give it a shot tomorrow since i am away from my main computer.

Java Variable Error

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