C4X5_DataSet.java

//DataSet.java      MrG 2011.1102
public class DataSet
{
    private int sum;
    private int count;

    /**
    Constructor: init sum and count
    */
    public DataSet()
    {
        this.sum = 0;
        this.count = 0;
    }

    /**
    Mutator: keep a running sum and count
    @param score is the current quiz
    */
    public void addValue(int score)
    {
        sum += score;
        count += 1;
    }

    /**
    Accessor:
    @return sum
    */
    public int getSum()
    {
        return sum;
    }

    /**
    Accessor:
    @return count
    */
    public int getCount()
    {
        return count;
    }

    /**
    Accessor: calculate average
    @return average
    */
    public double getAverage()
    {
        return (double)sum/count;
    }
}