Sale

Company: string

unitPrice: double

qty: int

salesAmt: double

Sale(string, double, int);

getCompany():string;

getUnitPrice():double;

getQty():int;

getSalesAmt():double;

computeRevenue():double;

HardwareSale

installFee: double

hWSale(string, double, int, double)

computeRevenue():double

Sale(string, double, int); 

Constructor  that initializes the respective data members to the pass in values.  salesAmt is set to 0.

getCompany():string;

Returns the company

getUnitPrice():double;

Returns the unit price

getQty():int;

Returns the quantity

getSalesAmt():double;

Returns the sales amount

computeRevenue():double;

Sets  sales amount = unit price * quantity.  Returns this computed value.

hWSale(string, double, int, double)

Invokes the base class constructor and sets install fees accordingly

computeRevenue():double

Sets  sales amount = unit price * quantity + install fees