Trouble with ArrayList

[John D.]

I am pretty new to ArrayLists so I am having a little trouble. In the writing of this program, I have happened upon a problem in the main method of the Tester class. In the Tester class, I am trying to print out the average monthly electric bill value. However, when I try to run it, I get an error stating: "calcAveragePrice(java.util.ArrayList<java.lang.Do uble>in CO2FromElectricitycannot be applied to()" I am wondering how to overcome this. If anybody has any ideas, I'd appreciate;)

Both classes that make up this program are shown below:

mport java.util.ArrayList;
public class CO2FromElectricityTester

{

//main method
    public static void main(String[ ] args)
    {
        //initialization of variables
        double total = 0.0;
        
        //create object
        CO2FromElectricity CO2 = new CO2FromElectricity();
        
        
                             
        System.out.printf("Average Monthly Electricity Bill: %11f",CO2.calcAveragePrice());
                                                    
        }//end of main method
    
}

/**
 * This program calculates my CO2 footprint based on the amount of electricity used in my home each year.
 * 
 * @author John D. Barry 
 * @version 03/18/2009
 */
import java.util.ArrayList; 
class CO2FromElectricity
{
    //declaration of private instance variables
    
    /**
     * Default constructor to create an object from the CO2FromElectricity class.
     */
    
    CO2FromElectricity()
    {
    }
    
    /**
     * A mutator method which calculates the average annual electricity bill.
     * @param monthlyBill an ArrayList containing the monthly bills for home electricity use.
     * @return the average monthly electricity bill.
     */
    public double calcAverageBill(ArrayList<Double> monthlyBill)
    {

        monthlyBill.add(279.41);
        monthlyBill.add(238.03);
        monthlyBill.add(248.64);
        monthlyBill.add(258.73);
        monthlyBill.add(395.48);
        monthlyBill.add(419.91);
        monthlyBill.add(431.15);
        monthlyBill.add(407.56);
        monthlyBill.add(417.14);
        monthlyBill.add(308.35);
        monthlyBill.add(337.91);
        monthlyBill.add(320.77);
        double sum = 0.0;
        double monthlyTotal = 0.0;
        
        for(int i=0; i < monthlyBill.size(); i++) 
        {
			sum += monthlyBill.get(i);
          }

          return monthlyTotal/monthlyBill.size(); 
}
        
     /**
     * A mutator method which calculates the average annual price of electricity.
     * @param monthlyPrice an ArrayList containing the monthly price of electricity per kilowatthour.
     * @return the average monthly price of electricity.
     */
    public double calcAveragePrice(ArrayList<Double> monthlyPrice)
    {
        monthlyPrice.add(0.1117);
        monthlyPrice.add(0.1107);
        monthlyPrice.add(0.1110);
        monthlyPrice.add(0.1113);
        monthlyPrice.add(0.1135);
        monthlyPrice.add(0.1138);
        monthlyPrice.add(0.1217);
        monthlyPrice.add(0.1215);
        monthlyPrice.add(0.1216);
        monthlyPrice.add(0.1228);
        monthlyPrice.add(0.1209);
        monthlyPrice.add(0.1192);
        double sum = 0.0;
        double monthlyTotal = 0.0;

       for(int i=0; i < monthlyPrice.size(); i++) 
        {
			sum += monthlyPrice.get(i);
          }

          return monthlyTotal/monthlyPrice.size();
    }
        
     /**
     * A mutator method which calculates the annual home CO2 emission from electricity.
     * @param avgBill the average monthly home electricity bill.
     * @param avgPrice the average montlyl price of home electricity.
     * @return the annual home CO2 emission from home electricity use.
     */
    public double calcElectricityCO2(double avgBill,
                                    double avgPrice)
    {
        return (avgBill/avgPrice) * 1.37 * 12;
    } 
    
 
}

[MuslimCoder]

Hello,
calcAverageBill takes in an ArrayList, you forgot to pass the method the ArrayList<double>..

 public double calcAverageBill(ArrayList<Double> monthlyBill)

:)

[John D.]

Yes, thank you. I thought I should pass a parameter when I call the method back up in the main method; however, I don't know parameter to pass to it because I have already done the entire calculation in the method. :(

[MuslimCoder]

Then you should modify it not to take in anything :)

[John D.]

Thanks. I thought about it for a-while and have come up with something I think will work. However, based on what I have, I get this output: [ CO2FromElectricityTester.main({ }) ]
Average Monthly Electricity Bill: 0.000000

...so I guess something is still hosed...

import java.util.ArrayList;
public class CO2FromElectricityTester

{

//main method
    public static void main(String[ ] args)
    {
        //initialization of variables

        
        
        //create object
        CO2FromElectricity CO2 = new CO2FromElectricity();
        
        ArrayList<Double> monthlyBill = new ArrayList<Double>();
        
        monthlyBill.add(279.41);
        monthlyBill.add(238.03);
        monthlyBill.add(248.64);
        monthlyBill.add(258.73);
        monthlyBill.add(395.48);
        monthlyBill.add(419.91);
        monthlyBill.add(431.15);
        monthlyBill.add(407.56);
        monthlyBill.add(417.14);
        monthlyBill.add(308.35);
        monthlyBill.add(337.91);
        monthlyBill.add(320.77);
        
        
        
        
                             
        System.out.printf("Average Monthly Electricity Bill: %11f",CO2.calcAverageBill(monthlyBill));
                                                    
        }//end of main method
    
}

/**
 * This program calculates my CO2 footprint based on the amount of electricity used in my home each year.
 * 
 * @author John D. Barry 
 * @version 03/18/2009
 */
import java.util.ArrayList; 
class CO2FromElectricity
{
    //declaration of private instance variables
    
    /**
     * Default constructor to create an object from the CO2FromElectricity class.
     */
    
    CO2FromElectricity()
    {
    }
    
    /**
     * A mutator method which calculates the average annual electricity bill.
     * @param monthlyBill an ArrayList containing the monthly bills for home electricity use.
     * @return the average monthly electricity bill.
     */
    public double calcAverageBill(ArrayList<Double> monthlyBill)
    {

        
        double sum = 0.0;
        double monthlyTotal = 0.0;
        
        for(int i=0; i < monthlyBill.size(); i++) 
        {
			sum += monthlyBill.get(i);
	
          }

        return monthlyTotal/monthlyBill.size(); 
}
        
     /**
     * A mutator method which calculates the average annual price of electricity.
     * @param monthlyPrice an ArrayList containing the monthly price of electricity per kilowatthour.
     * @return the average monthly price of electricity.
     */
    public double calcAveragePrice(ArrayList<Double> monthlyPrice)
    {
        monthlyPrice.add(0.1117);
        monthlyPrice.add(0.1107);
        monthlyPrice.add(0.1110);
        monthlyPrice.add(0.1113);
        monthlyPrice.add(0.1135);
        monthlyPrice.add(0.1138);
        monthlyPrice.add(0.1217);
        monthlyPrice.add(0.1215);
        monthlyPrice.add(0.1216);
        monthlyPrice.add(0.1228);
        monthlyPrice.add(0.1209);
        monthlyPrice.add(0.1192);
        double sum = 0.0;
        double monthlyTotal = 0.0;

       for(int i=0; i < monthlyPrice.size(); i++) 
        {
			sum += monthlyPrice.get(i);
          }

          return monthlyTotal/monthlyPrice.size();
    }
        
     /**
     * A mutator method which calculates the annual home CO2 emission from electricity.
     * @param avgBill the average monthly home electricity bill.
     * @param avgPrice the average montlyl price of home electricity.
     * @return the annual home CO2 emission from home electricity use.
     */
    public double calcElectricityCO2(double avgBill,
                                    double avgPrice)
    {
        return (avgBill/avgPrice) * 1.37 * 12;
    } 
    
 
}