The select method is a powerful method that automatically iterates through a collection in a Ruby program and extracts the values you want to retrieve. Enumerators are a fun and powerful way of working with collections in Ruby, and after you get used to implementing the methods, you'll be shocked at how efficient it is to integrate advanced functionality with a limited amount of code.
Before going into the section, I'm going to ask you a question. Say, you are given an array of integers and want to grab only the even integers. How can you do that in Ruby?
If you're coming from other programming languages, you would probably use a while loop to iterate through each element, and would check if that element meets the condition of being an even integer.
However, in Ruby, we don't have to go through all that trouble because we can use the...