Problem with class declaration...

[GT500FOMOCO]

I am writing a program that calculates your weight on another planet. I have to use the

Planet

class, but it doesn't work right. Here is the code:

public class Weight {

    public static void main(String[] args) {
        ConsoleReader keyboard = new ConsoleReader(System.in);

        System.out.print("\n\nWelcome to Weight-Watching on Other Planets!");

        int choice = 0;
        int weight = 0;
        int newWeight = 0;
        String prompt = "\n\n[1] Mercury\n" +
                        "[2] Venus\n" +
                        "[3] Mars\n" +
                        "[4] Jupiter\n" +
                        "[5] Saturn\n" +
                        "[6] Uranus\n" +
                        "[7] Neptune\n" +
                        "[8] Pluto\n" +
                        "[9] Quit\n\n" +
                        "Enter option: ";
        String prompt2 = "\nEnter earthly weight (in pounds): ";

        while (choice != 9) {
            choice = getChoice(prompt, keyboard);

            if (choice != 9) {
                weight = getWeight(prompt2, keyboard);
                Planet planet1 = new Planet(getPlanet(choice), getWeight(choice));
                newWeight = planet1.convert(weight);
                System.out.print("\nYour weight on " + getPlanet(choice)
                + " is " + newWeight + ".");
            }
        }
        System.out.print("\nGood-bye!");
    }

    public static int getChoice(String prompt, ConsoleReader keyboard) {
        System.out.print(prompt);
        int input = keyboard.readInt();

        return input;
    }

    public static int getWeight(String prompt, ConsoleReader keyboard) {
        System.out.print(prompt);
        int input = keyboard.readInt();

        return input;
    }

    public static double getWeight(int choice) {

        if (choice == 1) {
            return .378;
        }

        else if (choice == 2) {
            return .906;
        }

        else if (choice == 3) {
            return .379;
        }

        else if (choice == 4) {
            return 2.533;
        }

        else if (choice == 5) {
            return 1.066;
        }

        else if (choice == 6) {
            return .905;
        }

        else if (choice == 7) {
            return 1.133;
        }

        else {
            return .067;
        }
    }

    public static String getPlanet(int choice) {

        if (choice == 1) {
            return "Mercury";
        }

        else if (choice == 2) {
            return "Venus";
        }

        else if (choice == 3) {
            return "Mars";
        }

        else if (choice == 4) {
            return "Jupiter";
        }

        else if (choice == 5) {
            return "Saturn";
        }

        else if (choice == 6) {
            return "Uranus";
        }

        else if (choice == 7) {
            return "Neptune";
        }

        else {
            return "Pluto";
        }
    }

    class Planet {

        public Planet(String name, double weight) {
        }

        public int convert(int eweight) {
            int newWeight = eweight * weight;

            return newWeight;
        }

        private int weight;
    }
}

Here is the error message:

C:\Lesson9\Weight.java:28: non-static variable this cannot be referenced from a static context
                Planet planet1 = new Planet(getPlanet(choice), getWeight(choice));

"and everything under the sun is in tune
but the sun is eclipsed by the moon." --Pink Floyd: Eclipse

"I'm going to spend eternity
reinstalling Windows." --Reinstalling Windows: by some British guy

 

[godcomplex]

Don;t make the Palanet class a inner class of Weight. Try placing that code in another file or declare it after the Weight class and it should compile fine.

-gc "I don't look busy because I did it right the first time."

 

[GT500FOMOCO]

I fixed that problem...

Although now I have a new problem. The double weight won't carry it's variable over. I know this should work, here is the code for the class:

class Planet {

    public Planet(String name, double weight) {
    }

    public int convert(int eweight) {
        int newWeight = (int)(eweight * weight);

        return newWeight;
    }

    private double weight;
}

"and everything under the sun is in tune
but the sun is eclipsed by the moon." --Pink Floyd: Eclipse

"I'm going to spend eternity
reinstalling Windows." --Reinstalling Windows: by some British guy

 

[godcomplex]

In your constructor you should probably put the line:
this.weight = weight; It will proably work better if you assign your variable to what you passed in.

-gc "I don't look busy because I did it right the first time."

 

[Mayniac]

Try adding this.weight=weight; in your constructor.
The "weight" that your constructor is accepting is local to the constructot.

 

[GT500FOMOCO]

Thanks, but that just confused me...

Although I fixed the problem anyway. "and everything under the sun is in tune
but the sun is eclipsed by the moon." --Pink Floyd: Eclipse

"I'm going to spend eternity
reinstalling Windows." --Reinstalling Windows: by some British guy

 

[daniel135]

GT500FOMOCO,

Try a google search on switch statements and local variables, or see Sun's Java Tutorial.

Are you putting that in an Applet somewhere? that looks like a fun project!

"Don't bother measuring my productivity by lines of code -- it would be negative"

 

[GT500FOMOCO]

Can't use switch statements. I haven't learned them yet.

No, I'm not puting it in an Applet. It's just a good old fashioned MS-DOS program. "and everything under the sun is in tune
but the sun is eclipsed by the moon." --Pink Floyd: Eclipse

"I'm going to spend eternity
reinstalling Windows." --Reinstalling Windows: by some British guy