13.5 Focus on Software Engineering: Separating Class Specification from Implementation: 10889

Question

Write the implementation (.cpp file) of the  Averager class of the previous exercise. The full specification of the class is:
An data member named  sum of type integer.
An data member named  count of type integer.
A constructor with no parameters. The constructor initializes the data members  sum and the data member  count to 0.
A function named  getSum that accepts no parameters and returns an integer.  getSum returns the value of  sum .
A function named  add that accepts an integer parameter and returns no value.  add increases the value of  sum by the value of the parameter, and increments the value of  count by one.
A function named  getCount that accepts no parameters and returns an integer.  getCount returns the value of the  count data member, that is, the number of values added to  sum .
A function named  getAverage that accepts no parameters and returns a double.  getAverage returns the average of the values added to  sum . The value returned should be a value of type double (and therefore you must cast the data members to double prior to performing the division).

Solution
Averager::Averager()
{
    sum=0;
    count=0;
}

int Averager::getSum()
{
    return sum;
}

void Averager::add(int theNum)
{
    sum+=theNum;
    count++;
}

int Averager::getCount()
{
    return count;
}

double Averager::getAverage()
{
    return (double) sum / (double) count;
}