if/else issue

Question

lancevo3 0 Junior Poster

13 Years Ago

Hey guys I am writing my first program ever in java starting tonight and all has actually gone smooth which has been a surprise but I have run into a problem with an if else area. Basically, what I am suppose to be doing in this section is the user is prompted to either give r, d, or n and depending on their response they receive a different price. No matter what I input I get the price for n (which is 0.00). So I was wondering if anyone knows what might be wrong?

r = 1.00
d = 1.50
n = 0.00

Thank You in Advance!

System.out.println("Type of padding (r = regular, d = delux, n = none)?: ");
    padding = sc.next();

    System.out.println(padding);

    if (sqYard > 3000)
       {
       carpetCost = price * sqYard * surChargeBig;
       System.out.println(carpetCost);
       }
    else
       System.out.println("small");

    if (padding == "r")
      System.out.println(costRegPad);
    else if (padding == "d")
       System.out.println(costDlxPad);
    else
       System.out.println(0.00);

java

4 Contributors
15 Replies
142 Views
18 Hours Discussion Span
Latest Post 13 Years Ago Latest Post by lancevo3

insanely_sane 7 Junior Poster in Training

13 Years Ago

Is this your whole code? If yes, then umm... where have you defined the variables r, d, n? The computer wouldn't know what r,d,n are...
Also the following is wrong

if (padding == "r")

same goes for the ' == "d" '

only Strings are put in double quotes. if you have declared r as a variable with a value, then remove the quotes. I'm surprised your compiler didnt give you errors! anyhow, give me the whole code and I shall fix stuff....

insanely_sane 7 Junior Poster in Training

13 Years Ago

Not quite sure what the purpose of this program is but I can see a few mistakes which I pointed out in the previous comment.

if (padding == "r")
System.out.println(costRegPad);
else if (padding == "d")
System.out.println(costDlxPad);

THIS IS WRONG!!! On so many levels.
First, Only, ONLY, strings (something like "hello", "bye", "name") are put in double quotes. so remove those quotes.
Second, you want to compare 'char's ... so instead of putting double quotes, put single quotes. so that part changes to:

if (padding == 'r')
System.out.println(costRegPad);
else if (padding == 'd')
System.out.println(costDlxPad);

Those are the only mistakes I can see so far. See if it runs good now. If it doesn't then tell me the question you are working on.

insanely_sane 7 Junior Poster in Training

13 Years Ago

Since you are using 'Scanner' to get the input..

try defining what kind of input do you want. for example,

for integer:
sc.nextInt

for char:
sc.nextChar

maybe that would work. If not, I'm all out. I need to brush up my java O_O

EDIT: The error says that you are trying to compare a string value like a char value... try using something like

if (padding.equals("r"))

Edited 13 Years Ago by insanely_sane because: Just thought of something...

Akill10 96 Posting Pro

13 Years Ago

Using your old code, replace:

if (padding == "r")
System.out.println(costRegPad);
else if (padding == "d")
System.out.println(costDlxPad);

with

if (padding.equals("r"))
      System.out.println(costRegPad);
    else if (padding.equals("d"))
       System.out.println(costDlxPad);

To compare Strings you use .equals

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lancevo3 0 Junior Poster · Answer 1 · 2011-02-02T12:34:03+00:00

import java.io.*;
import java.util.Scanner;

public class RugCostEst1
  {

  //symbolic constants

  public static final double taxRate = 0.06;
  public static final int jobSize = 3000;
  public static final double surChargeBig = 1.05;
  public static final double surChargeReg = 1.07;
  public static final double costRegPad = 1.00;
  public static final double costDlxPad = 1.50;
  public static final double laborRate = 10.00;
  public static final double costMoving = 20.00;
 

  public static void main(String argv[])
    {
    String str,
           padding;

    double sqYard = 0.00,
           price = 0.00,
           numRooms = 0.00,
           moveFurniture = 0.00;

    double carpetCost = 0.00,
           laborCost = 0.00,
           preTaxTotal = 0.00,
           tax = 0.00;

    Scanner sc = new Scanner(System.in);

    System.out.println("How much carpet needed (in square feet)?: ");
    str = sc.next();

    sqYard = new Double(str).doubleValue();

    System.out.println("What is the price per square yard?: ");
    str = sc.next();

    price = new Double(str).doubleValue();

    System.out.println("Number of rooms?: ");
    str = sc.next();

    numRooms = new Double(str).doubleValue();

    System.out.println("How many rooms need furniture moved?: ");
    str = sc.next();

    moveFurniture = new Double(str).doubleValue();

    System.out.println("Type of padding (r = regular, d = delux, n = none)?: ");
    padding = sc.next();
 
    System.out.println(padding);

    if (sqYard > 3000)
       {
       carpetCost = price * sqYard * surChargeBig;  
       System.out.println(carpetCost);
       }   
    else
       System.out.println("small");

    if (padding == "r")
      System.out.println(costRegPad);
    else if (padding == "d")
       System.out.println(costDlxPad);
    else
       System.out.println(0.00);


/*


    laborCost = (numRooms * laborRate) + (costMoving * moveFurniture);  
    System.out.println(laborCost);

    //preTaxTotal = carpetCost + paddingCost + laborCost;
    //System.out.println(preTaxTotal);

    //tax = preTaxTotal * taxRate;
    //System.out.println(tax);

    //total = preTaxTotal + tax;
    //System.out.println(total);
*/
    }
  }

lancevo3 0 Junior Poster · Answer 2 · 2011-02-02T12:56:28+00:00

I get this error for both now.

RugCostEst1.java:69: incomparable types: java.lang.String and char
if (padding == 'r')

Any idea?

Thanks

lancevo3 0 Junior Poster · Answer 3 · 2011-02-03T00:09:47+00:00

Ya I tried boht of those still having a few issues.

lancevo3 0 Junior Poster · Answer 4 · 2011-02-03T00:32:14+00:00

I did something just like that right before you posted it and now I recieve this error:

Exception in thread "main" java.lang.NoClassDefFoundError: RugCostEst1/java
Caused by: java.lang.ClassNotFoundException: RugCostEst1.java
at java.net.URLClassLoader$1.run(URLClassLoader.java:202)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
at java.lang.ClassLoader.loadClass(ClassLoader.java:307)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301)
at java.lang.ClassLoader.loadClass(ClassLoader.java:248)
Could not find the main class: RugCostEst1.java. Program will exit.

Here is my updated code.

Thanks

import java.io.*;
import java.util.Scanner;

public class RugCostEst1
  {

  //symbolic constants

  public static final double taxRate = 0.06;
  public static final int jobSize = 3000;
  public static final double surChargeBig = 1.05;
  public static final double surChargeReg = 1.07;
  public static final double costRegPad = 1.00;
  public static final double costDlxPad = 1.50;
  public static final double laborRate = 10.00;
  public static final double costMoving = 20.00;
 
 
  public static void main(String argv[])
    {
    String str,
           regular = "r",
           deluxe = "d",
           padding;

    double sqYard = 0.00,
           price = 0.00,
           numRooms = 0.00,
           moveFurniture = 0.00;

    double carpetCost = 0.00,
           laborCost = 0.00,
           preTaxTotal = 0.00,
           tax = 0.00;

    Scanner sc = new Scanner(System.in);

    System.out.println("How much carpet needed (in square feet)?: ");
    str = sc.next();

    sqYard = new Double(str).doubleValue();

    System.out.println("What is the price per square yard?: ");
    str = sc.next();

    price = new Double(str).doubleValue();

    System.out.println("Number of rooms?: ");
    str = sc.next();

    numRooms = new Double(str).doubleValue();

    System.out.println("How many rooms need furniture moved?: ");
    str = sc.next();

    moveFurniture = new Double(str).doubleValue();

    System.out.println("Type of padding (r = regular, d = delux, n = none)?: ");
    padding = sc.next();
 
    System.out.println(padding);

    if (sqYard > 3000)
       {
       carpetCost = price * sqYard * surChargeBig;  
       System.out.println(carpetCost);
       }   
    else
       System.out.println("small");

    if (padding.equals(regular))
      System.out.println(costRegPad);
    else if (padding.equals(deluxe))
       System.out.println(costDlxPad);
    else
       System.out.println(0.00);





    laborCost = (numRooms * laborRate) + (costMoving * moveFurniture);  
    System.out.println(laborCost);

    //preTaxTotal = carpetCost + paddingCost + laborCost;
    //System.out.println(preTaxTotal);

    //tax = preTaxTotal * taxRate;
    //System.out.println(tax);

    //total = preTaxTotal + tax;
    //System.out.println(total);

    }
  }

Akill10 96 Posting Pro · Answer 5 · 2011-02-03T00:47:10+00:00

It compiles fine for me? Have you missed/removed a { from anywhere? Are you sure you copied the exact same code you have now?

lancevo3 0 Junior Poster · Answer 6 · 2011-02-03T00:49:34+00:00

it compiles fine for me but that error comes when i execute it

Akill10 96 Posting Pro · Answer 7 · 2011-02-03T00:55:28+00:00

Ok, can you tell me how you produce that error? The steps. The program works fine for me.

jon.kiparsky 326 Posting Virtuoso · Answer 8 · 2011-02-03T00:57:46+00:00

That code looks like it should compile okay - did you maybe have a command-line typo when you went to compile or run?

lancevo3 0 Junior Poster · Answer 9 · 2011-02-03T00:57:51+00:00

I literally just run the compile command and then when I execute it comes up.

z136340@turing:~/CS470$ javac RugCostEst1.java

z136340@turing:~/CS470$ java RugCostEst1.java

Exception in thread "main" java.lang.NoClassDefFoundError: RugCostEst1/java
Caused by: java.lang.ClassNotFoundException: RugCostEst1.java
at java.net.URLClassLoader$1.run(URLClassLoader.java:202)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
at java.lang.ClassLoader.loadClass(ClassLoader.java:307)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301)
at java.lang.ClassLoader.loadClass(ClassLoader.java:248)
Could not find the main class: RugCostEst1.java. Program will exit.

jon.kiparsky 326 Posting Virtuoso · Answer 10 · 2011-02-03T01:01:26+00:00

z136340@turing:~/CS470$ java RugCostEst1.java Remove ".java" from this and it'll work.

lancevo3 0 Junior Poster · Answer 11 · 2011-02-03T01:01:54+00:00

Ya that did it I literally just realized that before you guys posted it. Thanks for the help!