By Alexander Shvets

Design patterns help you solve commonly-occurring problems in software design. But you can’t just find a pattern and copy it into your program, the way you can with off-the-shelf functions or libraries. A pattern is not a specific piece of code, but a general concept for solving a particular problem. They are like pre-made blueprints that you can customize to solve a recurring design problem in your code.

The book Dive Into Design Patterns illustrates 22 classic design patterns, and 8 design principles that these patterns are based on.