Variable may not of been initialized even though it has been in the method

Question

When I compile the code it tells me I have 2 errors, both variable may not of been initialized errors. Variables celsius and fahrenheit are the problems. I believe I have already initialized them in their respective methods.

import java.io.*;

class Converter
{

double celsius,fahrenheit,temperature,inFahrenheit,inCelsius;

double Celsius (double temperature)
    {
    celsius  = (5.0 / 9.0) * (temperature - 32);
    return celsius;
    }
double Fahrenheit (double temperature)
    {
    fahrenheit = (9.0 / 5.0) * temperature + 32;
    return fahrenheit;
    }
}



 public class ConverterTester
{
public static void main(String[] args)throws IOException
{
    double temperature,fahrenheit,celsius;

    InputStreamReader inStream = new InputStreamReader (System.in);
    BufferedReader stdin = new BufferedReader (inStream);

    String intemperature,inCelciusOrFahrenheit;

    System.out.println("What is the temperature");
    intemperature = stdin.readLine();
    temperature = Double.parseDouble(intemperature);

    System.out.println("What is the temperature you wish to convert to, Celsius or Fahrenheit");
    inCelciusOrFahrenheit = stdin.readLine();


if (inCelciusOrFahrenheit.equals("Celsius"))
    {
    Converter Conversion1 = new Converter();
    Conversion1.Celsius(celsius);
    System.out.println("Your new temperature is " + celsius);
    }

else if(inCelciusOrFahrenheit.equals("Fahrenheit"))
    {   
    Converter Conversion2 = new Converter();
    Conversion2.Fahrenheit(fahrenheit);
    System.out.println("Your new temperature is " + fahrenheit);
    }
else 
    {
    System.out.println("Please enter a correct temperature");
    System.exit(0);
    }
}
}

The errors occur when I call the Celsius method and Fahrenheit method, I'm not sure if I'm allowed to use the variables when I call the methods. I however have not been able to find anything saying it is not allowed though.

Why do you think equal variable names mean that they are _exactly_ the same? And your logic doesn't even make sense. This method call here: `Conversion1.Celsius(celsius)` for example. That uninitialized variable is passed as `temperature` into `Celsius` where you assume you initialze the same `celsius` variable using the one from `ConverterTester`. Thus you take an uninitialized variable to initialize itself? — Tom, Oct 15 '17 at 21:28
Another problem you're about to run into: https://stackoverflow.com/questions/513832/how-do-i-compare-strings-in-java — azurefrog, Oct 15 '17 at 21:33

score 0 · Answer 1 · answered Oct 15 '17 at 21:37

0

Your only problem is that you didn't initialize temperature, celsius, or farenheit.
When making your variables here:
double celsius,fahrenheit,temperature,inFahrenheit,inCelsius;, you need to make temperature equal to something, say 20.
I would recommend to take out the ints celsius and farenheit, or set them equal to the doubles Celsius and Farenheit, that you set equal to temperature...math.

answered Oct 15 '17 at 21:37

I see your point, however temperature needs to be equal to the user input(in this case the buffered reader stdin) did I just place that statement in the wrong place or totally misuse it? And the Celsius and Fahrenheit are supposed to be methods, not variables. – Dks1 Oct 15 '17 at 22:09
@Dks1 of course, I was merely pointing out what you need to do – Oct 15 '17 at 22:16
@ ProgrammingNub ok thank you, I did not understand that. So my statement 'temperature =Double.ParseDouble(intemperature);' needs to be elsewhere? or set Celsius and Fahrenheit to temperature? – Dks1 Oct 15 '17 at 22:20

Variable may not of been initialized even though it has been in the method

1 Answers1