ABSTRACT
Understanding the concept of abstraction is critical for improving your capabilities as a programmer. The ability to express our thoughts in more abstract ways is a significant part of what has allowed modern software systems to scale to the size they are today. Abstraction comes in many forms, and you have dealt a little with abstraction already. At the simplest level, writing a function or a method that takes arguments is a form of abstraction. The one function can work for as many values as you want. Consider the basic example of a function that squares numbers. You can write the code 3 * 3 or 5 * 5, but a function like the following is an abstract representation of that procedure for the Double type.
