10.15. Wrap-Up

In this chapter, you learned how to overload operators to work with class objects. We demonstrated standard C++ class string, which makes extensive use of overloaded operators to create a robust, reusable class that can replace C strings. Next, we discussed several restrictions that the C++ standard places on overloaded operators. We then presented a PhoneNumber class that overloaded operators << and >> to conveniently output and input phone numbers. You also saw a Date class that overloaded the prefix and postfix increment (++) operators and we showed a special syntax that’s required to differentiate between the prefix and postfix versions of the increment (++) operator.

Next, we introduced the concept of dynamic memory management. You learned that you can create and destroy objects dynamically with the new and delete operators, respectively. Then, we presented a capstone Array class case study that used overloaded operators and other capabilities to solve various problems with pointer-based arrays. This case study helped you truly understand what classes and object technology are all about—crafting, using and reusing valuable classes. As part of this class, you saw overloaded stream insertion, stream extraction, assignment, equality and subscript operators.

You learned reasons for implementing overloaded operators as member functions or as non-member functions. The chapter concluded with discussions of converting between types (including class types), problems with certain implicit conversions defined by single-argument constructors and how to prevent those problems by using explicit constructors.

In the next chapter, we continue our discussion of classes by introducing a form of software reuse called inheritance. We’ll see that when classes share common attributes and behaviors, it’s possible to define those attributes and behaviors in a common “base” class and “inherit” those capabilities into new class definitions, enabling you to create the new classes with a minimal amount of code.