To shed some light on the practice of using `let` vs. `var`, an excerpt from the book by Apple: “If a stored value in your code is not going to change, always

To shed some light on the practice of using `let` vs. `var`, an excerpt from the book by Apple: “If a stored value in your code is not going to change, always declare it as a constant with the let keyword. Use variables only for storing values that need to be able to change.” Excerpt From: Apple Inc. “The Swift Programming Language.” iBooks. https://itun.es/us/jEUH0.l https://itun.es/us/jEUH0.l