Solved

Not sure about this error??

Posted on 2006-11-16
5
184 Views
Last Modified: 2010-03-31
I cannot figure out why I'm getting these two errors:

temp.java:84: operator || cannot be applied to java.lang.String,java.lang.String
                  if (scale="f"||"F")
                                     ^
temp.java:84: incompatible types
found   : java.lang.String
required: boolean
                  if (scale="f"||"F")
                                                                   ^
Here is my code:



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

public class temp
{
   

      public static float celciusToFahrenheit(float degCelc)
          {
              float degFahr;
              degFahr= degCelc * 9/5 + 32;
              return degFahr;
          }


      public static float fahrenheitToCelcius(float degFahr)
          {
              float degCelc;
              degCelc=(degFahr-32) *5/9;
              return degCelc;
          }
 

      public static float celciusToKelvin(float degCelc)
          {
              float degKelv;
              degKelv=degCelc+273.15f;
              return degKelv;
          }

      public static float kelvinToCelcius(float degKelv)
          {
              float degCelc;
              degCelc = degKelv - 273.15f;
              return degCelc;
          }






      public static void main(String[] args)
           {
             final int SENTINEL = 2004;
            int temp;
            String scale;
            String tempStr;
            String outputStr;
            String inputStr;
            String inputStr2;
            float fahr;
            float celc;
            float kelv;
 



      inputStr="Please enter a temperature less than or equal to 2003.";
      inputStr2="Please enter the scale:  c,C=celcius, f,F=fahrenheit, k,K=kelvin.";
      tempStr=JOptionPane.showInputDialog(inputStr+"  Enter 2004 to quit.");
      scale=JOptionPane.showInputDialog(inputStr2);
      temp=Integer.parseInt(tempStr);
      

      while (temp<=2003 && temp!=SENTINEL);
      {
                  if (scale="f"||"F")
                  {
                        fahr=temp;
                        celc=fahrenheitToCelcius(temp);
                        kelv=celciusToKelvin(celc);
                        outputStr="Temperature:  "+temp+"/n"
                         +"Scale:  "+scale+"/n"
                         +"Temperature in F is: "+"%2f,fahr"+"/n"
                         +"Temperature in C is: "+"%2f,celc"+"/n"
                         +"Temperature in K is: "+"%2f,kelv"+"/n";
                  }
            

      
      
      }
        
      
      JoptionPane.showMessageDialog(null,outputStr,"Your Conversions",JOption.PLAIN_MESSAGE);



     }
      
}


0
Comment
Question by:jasonbrandt3
5 Comments
 

Expert Comment

by:firas_fas
ID: 17962009
try replacing  if (scale="f"||"F") with :

if (scale.equals("f") || scale.equals("F"))
0
 
LVL 23

Accepted Solution

by:
Ajay-Singh earned 500 total points
ID: 17962087
>                if (scale="f"||"F")
if you want to check if scale is "f" or "F", use the following

if("f".equalsIgnoreCase(scale))
0
 

Author Comment

by:jasonbrandt3
ID: 17965431
The first suggestion seemed to work.  I'm getting another error.  I changed some things.  Here is the error I'm now getting:
(PLEASE HELP!!!!!)  I thought the outputStr is initialized in the If loop........

temp.java:102: variable outputStr might not have been initialized
      JOptionPane.showMessageDialog(null,outputStr,"Your Conversions",JOptionPane.INFORMATION_MESSAGE);
                                           ^
1 error



Here is my new code:

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

public class temp
{
   

      public static float celciusToFahrenheit(float degCelc)
          {
              float degFahr;
              degFahr= degCelc * 9/5 + 32;
              return degFahr;
          }


      public static float fahrenheitToCelcius(float degFahr)
          {
              float degCelc;
              degCelc=(degFahr-32) *5/9;
              return degCelc;
          }
 

      public static float celciusToKelvin(float degCelc)
          {
              float degKelv;
              degKelv=degCelc+273.15f;
              return degKelv;
          }

      public static float kelvinToCelcius(float degKelv)
          {
              float degCelc;
              degCelc = degKelv - 273.15f;
              return degCelc;
          }






      public static void main(String[] args)
           {
             final int SENTINEL = 2004;
            int temp;
            String scale;
            String tempStr;
            String outputStr;
            String inputStr;
            String inputStr2;
            float fahr;
            float celc;
            float kelv;
 



      inputStr="Please enter a temperature less than or equal to 2003.";
      inputStr2="Please enter the scale:  c,C=celcius, f,F=fahrenheit, k,K=kelvin.";
      tempStr=JOptionPane.showInputDialog(inputStr+"  Enter 2004 to quit.");
      scale=JOptionPane.showInputDialog(inputStr2);
      temp=Integer.parseInt(tempStr);
        

      while (temp<=2003 && temp!=SENTINEL);
      {
                  if (scale.equals("f") || scale.equals("F"))
                  {
                        fahr=temp;
                        celc=fahrenheitToCelcius(temp);
                        kelv=celciusToKelvin(celc);
                        outputStr=String.format("Temperature:  "+temp+"/n")
                        +String.format( "Scale:  "+scale+"/n")
                        +String.format( "Temperature in F is: "+"%2f",fahr)+"/n"
                        +String.format( "Temperature in C is: "+"%2f",celc)+"/n"
                        +String.format( "Temperature in K is: "+"%2f",kelv)+"/n";
                  }
            

      
      
      }
      
      
      JOptionPane.showMessageDialog(null,outputStr,"Your Conversions",JOptionPane.INFORMATION_MESSAGE);



     }
      
      
}

0
 
LVL 6

Expert Comment

by:SamsonChung
ID: 17965954
Strings can not be || ...

you can use the equal method, where firas aor Ajay suggested.

other then that.... that's basiclaly your problem there.
0
 

Expert Comment

by:firas_fas
ID: 17966747
The fact that the first time you initialize the variable outputStr is inside of an if statement causes this problem.

Where you define all your variables in the main method, try replacing:
String outputStr;

with:
String outputStr="";

This should get rid of the error.

You may also want to add to your if statement block ( if you want to accept the three types of scales from user). If you want to do that then replace this:

               if (scale.equals("f") || scale.equals("F"))
               {
                    
                    
                    fahr=temp;
                    celc=fahrenheitToCelcius(temp);
                    kelv=celciusToKelvin(celc);
                    outputStr="Temperature:  "+temp+"/n"
                    +"Scale:  "+scale+"/n"
                    +"Temperature in F is: "+ fahr+"/n"
                    + "Temperature in C is: "+celc +"/n"
                    + "Temperature in K is: "+ kelv +"/n";
               }

with:

               if (scale.equals("f") || scale.equals("F"))
               {
                    
                    
                    fahr=temp;
                    celc=fahrenheitToCelcius(temp);
                    kelv=celciusToKelvin(celc);
                    outputStr="Temperature:  "+temp+"/n"
                    +"Scale:  "+scale+"/n"
                    +"Temperature in F is: "+ fahr+"/n"
                    + "Temperature in C is: "+celc +"/n"
                    + "Temperature in K is: "+ kelv +"/n";
               }else if (scale.equals("c") || scale.equals("C")){
                     .....
                   do conversion
                  ......
               }else if (scale.equals("f") || scale.equals("F")){
                     .....
                   do conversion
                  ......
               }else{
                     outputStr="You Did not enter a scale\n";
               }
0

Featured Post

Free Tool: Subnet Calculator

The subnet calculator helps you design networks by taking an IP address and network mask and returning information such as network, broadcast address, and host range.

One of a set of tools we're offering as a way of saying thank you for being a part of the community.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Title # Comments Views Activity
Weekend adv creator 3 54
ejb example issues 3 28
Is Applet the way to go for my drag and drop system? 8 25
Crystal Reports Licensing Questions 4 37
For customizing the look of your lightweight component and making it look opaque like it was made of plastic.  This tip assumes your component to be of rectangular shape and completely opaque.   (CODE)
INTRODUCTION Working with files is a moderately common task in Java.  For most projects hard coding the file names, using parameters in configuration files, or using command-line arguments is sufficient.   However, when your application has vi…
Viewers will learn about the different types of variables in Java and how to declare them. Decide the type of variable desired: Put the keyword corresponding to the type of variable in front of the variable name: Use the equal sign to assign a v…
This tutorial will introduce the viewer to VisualVM for the Java platform application. This video explains an example program and covers the Overview, Monitor, and Heap Dump tabs.

820 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question