Lecture 2

Learning objectives

After this class (which reviews C++ material that you should already know!), you should be able to:

1. Describe the concept of an abstract data type, and how C++ classes help implement them.
2. Mention two benefits of data hiding.
3. Mention which type of file typically contains the interface, and which the implementation, in C++.
4. Explain why templates are normally defined in .h files.
5. Define and use template functions and classes.
6. Give examples of some common errors with the use of pointers.
7. Given code with incorrect use of pointers, identify the problems and correct them.
8. Explain when "deep copy" is needed, why it is needed, and what are the typical features that need to be implemented to ensure deep copy.
9. Explain why self-assignment can lead to incorrect code, when we overload assignment to ensure deep copy.
10. Explain how a friend function is different from others.

Reading assignment

1. Chapter 1, up to sec 1.6 (except sec 1.3 and 1.5).
2. Optional: Fall 2003 lecture notes has additional explanations for templates (chapter 5), and on deep copy (chapter 2).

Exercises and review questions

• Exercises and review questions on current lecture's material
  1. What are two benefits of information hiding?
  2. Will the interface normally be in a .h file or in a .cpp file?
  3. Will the implementation normally be in a .h file or in a .cpp file?
  4. Why are templates normally defined in .h files?
  5. Comment out the header file guards in largest.h, include largest.h twice in uselargest.cpp, and try compiling. Why does it not compile?
  6. Write a template function called average, which computes the average of an array, and give an example code demonstrating its use.
  7. Write a template class called complex, which stores a complex number. The components may either be int, float, or double. Include an operator for adding two complex numbers, and for outputting a complex number. (Note: A complex number is a pair of numbers (x,y). The sum of complex numbers c₁ = (x₁, y₁) and c₂ = (x₂, y₂) is defined as the complex number (x₁+x₂, y₁+y₂).)
  8. Chapter 1, exercise #10. Also, fix the error.
  9. Why was the operator << made a friend in the Pair class?

• Questions on next lecture's material
  1. Can you find out where the STL header files are, on the machine linprog?