Chapter 9, Problem 3E

Create an application named SalesTransactionDemo that declares several SalesTransaction objects and displays their values and their sum. The SalesTransaction class contains fields for a salesperson name, sales amount, and commission and a readonly field that stores the commission rate. Include three constructors for the class. One constructor accepts values for the name, sales amount, and rate, and when the sales value is set, the constructor computes the commission as sales value times commission rate. The second constructor accepts a name and sales amount, but sets the commission rate to 0. The third constructor accepts a name and sets all the other fields to 0. An overloaded + operator adds the sales values for two SalesTransaction objects.