The first module in this course presents you with the groundwork in preparation for the material that you will be reading.
Course goals In this course you will learn what the GOF (Gang of Four) patterns are and how they help solve common problems encountered in object-oriented design.

After completing this course, you'll be able to:

1. Use creational patterns to create objects when constructors will not serve your purpose.
2. 
   Behavioral patterns characterize the ways in which classes or objects interact and distribute responsibility.
   You will learn how to use behavioral patterns to reduce complicated flow control.
3. 
   Furthermore, you will use behavioral patterns to encapsulate algorithms and dynamically select them at run time.
4. 
   Structural patterns deal with the composition of classes or objects.
5. The 2 most common techniques for reusing functionality in object-oriented systems are
   1. Class Inheritance and
   2. Object Composition
6. You will learn how to use the Gang of Four Pattners (Design Patterns) to replace inheritance with composition.

1. composition: Creating objects with other objects as members. Composition should be used when a has-relationship applies
2. inheritance: The concept of classes automatically containing the variables and methods defined in their supertypes.