Design patterns let programmers avoid re-inventing the wheel. The original book (Design Patterns by the \"Gang of Four\": Erich Gamma, Richard Helm, Ralph Johnson, and John Vlissides) was phenomenally successful. When the programmer faces a particular problem, all they have to do is to look up the correct matching design pattern and use it to implement the solution. In this tutorial VTC author guides you through the most popular and useful design patterns, so you can begin incorporating them into your own code.