[RESOLVED] Beginner Homework issue

Hi,

I have only been learning Java as part of my software development course for 3 weeks. I have to hand an exercise I have to hand it in by next week except I don't understand the errors I'm receiving.

This is my code:

Java main:

Code:

---

public class NewMain {

    /**
    * @param args the command line arguments
    */
    public static void main(String[] args) {
              Unit unit;
                unit = new Unit();
                unit.setmaintainenceCost(100);
                unit.getrentAmount(60);
                unit.setnumRooms(1);
                unit.setunitCost("Hundred");
                       
        System.out.println("Rent amount: = " + unit.getunitCost());
        System.out.println("Room number: = " + unit.getnumRooms(numRooms));
              System.out.println("maintainenceCost: = " + unit.getmaintainenceCost());
        System.out.println("unitCost = " + unit.getunitCost(null));
    }

}

---

Class:

Code:

---

public class Unit {
    //constants

    public static final String DEFAULT_UNIT_COST = "DEFAULT_UNIT_COST";
    public static final int DEFAULT_NUM_ROOMS= 0;
    public static final int DEFAULT_RENT_AMOUNT= 0;
    public static final int DEFAULT_MAINTAINENCE_COST= 0;

    //instance variables
    private int rentAmount;
    private int numRooms;
    private int maintainenceCost;
    private String unitCost;

    //no arg constructor
    public Unit() {

    }

    // all arg constructor
    public Unit(int rentAmount, int numRooms, int maintainenceCost, String unitCost) {
        this.rentAmount = rentAmount;
        this.numRooms =  numRooms;
        this.maintainenceCost = maintainenceCost;
        this.unitCost = unitCost;
    }

    //getter for numRooms
    public int getnumRooms(int numRooms) {
        return this.numRooms;
    }
    //setter for numRooms

    public void setnumRooms(int numRooms) {
        this.numRooms = numRooms;
    }

        //getter for rentAmount
    public int getrentAmount(int rentAmount) {
        return this.rentAmount;
    }
    //setter for rentAmount

    public void setrentAmount(int rentAmount) {
        this.rentAmount = rentAmount;
    }
          //getter for maintainenceCost
    public int getmaintainenceCost(int maintainenceCost) {
        return this.maintainenceCost;
    }
    //setter for maintainenceCost

    public void setmaintainenceCost(int maintainenceCost) {
        this.maintainenceCost = maintainenceCost;
    }
        public String getunitCost(String unitCost) {
        return this.unitCost;
    }
    //setter for maintainenceCost

    public void setunitCost(String unitCost) {
        this.unitCost = unitCost;
    }
    //toString method used for debugging
    public String toString() {
        return super.toString() +
                "[" +
                "\n rentAmount = " + this.rentAmount  +
                "\n numRooms = " + this.numRooms +
                "\n maintainenceCost = " + this.maintainenceCost +
                "\n unitCost = " + this.unitCost.toString() +
                "]";
    }
}

---

Thanks,



Nightwalker

Just looking at the code here I notice a few things.

#1 You're not passing anything into your function "getunitCost," which you've written to require a string parameter.
#2 You're using the variable "numRooms" and you've never declared it anywhere nor have you assigned it anything.
#3 "getmaintainenceCost" requires an integer parameter, which you haven't given.

If you look at the unit class, it defines what you need to pass and how you need to handle everything. You don't seem to be following it in your "NewMain" class.

Using the follow code it works!

Java main:

Code:

---

public class NewMain {

    /**
    * @param args the command line arguments
    */
    public static void main(String[] args) {
              Unit unit;
                unit = new Unit();
                unit.setmaintainenceCost(100);
                unit.setrentAmount(6);
                unit.setnumRooms(1);
                unit.setunitCost("Hundred");
                       
        System.out.println("Rent amount: = " + unit.getunitCost(null));
        System.out.println("Room number: = " + unit.getnumRooms(1));
              System.out.println("maintainenceCost: = " + unit.getmaintainenceCost(1));
        System.out.println("unitCost = " + unit.getunitCost(null));
    }

}

---

Class:

Code:

---

public class Unit {
    //constants

    public static final String DEFAULT_UNIT_COST = "DEFAULT_UNIT_COST";
    public static final int DEFAULT_NUM_ROOMS= 0;
    public static final int DEFAULT_RENT_AMOUNT= 0;
    public static final int DEFAULT_MAINTAINENCE_COST= 0;

    //instance variables
    private int rentAmount;
    private int numRooms;
    private int maintainenceCost;
    private String unitCost;

    //no arg constructor
    public Unit() {

    }

    // all arg constructor
    public Unit(int rentAmount, int numRooms, int maintainenceCost, String unitCost) {
        this.rentAmount = rentAmount;
        this.numRooms =  numRooms;
        this.maintainenceCost = maintainenceCost;
        this.unitCost = unitCost;
    }

    //getter for numRooms
    public int getnumRooms(int numRooms) {
        return this.numRooms;
    }
    //setter for numRooms

    public void setnumRooms(int numRooms) {
        this.numRooms = numRooms;
    }

        //getter for rentAmount
    public int getrentAmount(int rentAmount) {
        return this.rentAmount;
    }
    //setter for rentAmount

    public void setrentAmount(int rentAmount) {
        this.rentAmount = rentAmount;
    }
          //getter for maintainenceCost
    public int getmaintainenceCost(int maintainenceCost) {
        return this.maintainenceCost;
    }
    //setter for maintainenceCost

    public void setmaintainenceCost(int maintainenceCost) {
        this.maintainenceCost = maintainenceCost;
    }
        public String getunitCost(String unitCost) {
        return this.unitCost;
    }
    //setter for maintainenceCost

    public void setunitCost(String unitCost) {
        this.unitCost = unitCost;
    }
    //toString method used for debugging
    public String toString() {
        return super.toString() +
                "[" +
                "\n rentAmount = " + this.rentAmount  +
                "\n numRooms = " + this.numRooms +
                "\n maintainenceCost = " + this.maintainenceCost +
                "\n unitCost = " + this.unitCost.toString() +
                "]";
    }
}

---

Although, I don't know why I am receiving "Rent amount: = Hundred" not matter what value I set Rent amount to. Also, Rent amount is suppose to be an int not string. I'm going to have to compare my code with my class mates code and see if we both get the same answer.

Because you're calling unitCost, not rentAmount.

Code:

---

"Rent amount: = " + unit.getunitCost(null)

---

Will always equal what you've assigned it, which you do here:

Code:

---

unit.setunitCost("Hundred");

---

I assume what you want, is to call "getrentAmount()." Mind you, I don't know why you're passing it an integer parameter that you never use.

I replaced that line with:

Code:

---

System.out.println("Rent amount: = " + unit.getrentAmount(1));

---

and it works.