problems accessing class instances
 

I'm having a problem whereby I create an instance of a class called Calculations.class in one of my main classes, but cannot access that instance from any other class. Here is the code

public class Parameters{
//code//
Calculations calc = new Calculations();
//some calculations done using variables in the calculations class and new data is saved//
//end of Parameters.class//
}

public class Intake{
// I now want to work with the instance "calc" created above so I can use the variables that were set in Parameters.class, but I don't know how to reference this instance!! //

Any help will be greatly appreciated, thank you!!

Re: problems accessing class instances
 

You could make a method in your parameters class called getCalculator, which simply returns the calculator -

public Calculator getCalculator()
{
return calc;
}

Then create an instance of parameters in intake and call the getCalculator method upon it.

Parameters pram = new Parameters();
Calculators calc2 = new Calculators();
calc2 = pram.getCalculator();

Hopefully that will help. :)

Re: problems accessing class instances
 

Hi, it almost helps, but when I try and run the program, it comes up with:

Intake.java [189:1] <identifier> expected
calc = pram.getCalculator();
^
1 error
Errors compiling Intake.

Re: problems accessing class instances
 

public Calculator getCalculator()
{
return calc;
}

You never declare what 'calc' is.

public Calculator getCalculator()
{
Calculator calc;
return calc;
}

However I would assume that you would assign something to 'calc'?

Re: problems accessing class instances
 

it would have to be the calculator created in parameters so

public Calculator getCalculator()
{
Calculator calc1;
calc1 = calc;
return calc1;
}

hows that? but then if its been declared public at the top you should just be able to return calc. :S what you reckon?

Re: problems accessing class instances
 

I think what you have is an issue of scope.

Looking at the above, I think you placed the getCalculator method in the wrong class. It should go in the Parameters Class.

So you would have the following:

public class Parameters{

   Calculations calc = new Calculations();

   //some calculations done using variables in the calculations class 

   //and new data is saved 



   public Calculations getCalculator() {

      return calc;

   }

} //end of Parameters.class



public class Intake{

   // I now want to work with the instance "calc" created above so I can 

   // use the variables that were set in Parameters.class, but I don't know

   // how to reference this instance!!

   Parameters pram = new Parameters();

   Calculators calc2 = new Calculators();

   calc2 = pram.getCalculator(); 

}

Re: problems accessing class instances
 

Still doesn't work, even with the modifications given above. I still work on it though, must be some way round it!!

Re: problems accessing class instances
 

Opps, I mispelled, Calculations

The second class should be:

public class Intake{

   // I now want to work with the instance "calc" created above so I can 

   // use the variables that were set in Parameters.class, but I don't know

   // how to reference this instance!!

   Parameters pram = new Parameters();

   Calculations calc2 = new Calculations();

   calc2 = pram.getCalculator(); 

}

Also I suspect you have Calculations defined somewhere?

Re: problems accessing class instances
 

Yes, calculations is defined elsewhere. However, when I add the code you provided me with(very grateful!!), the compiler returns with an error saying that an identifier is missing before the line of code:

calc2 = pram.getCalculator();

What do I need to do now?

Re: problems accessing class instances
 

Actually you dont even need to assign (I was getting an error too.) This does compile:

public class Intake{

    // I now want to work with the instance "calc" created above so I can 

    // use the variables that were set in Parameters.class, but I don't know

    // how to reference this instance!!

    Parameters pram = new Parameters();

    Calculations calc2 = pram.getCalculator(); 

    // or you could even say (since calc is public)

    Calculations calc3 = pram.calc; 

}