Learn Ruby the Hard Way: A Simple and Idiomatic Introduction to the Imaginative World of Computational Thinking with Code, Third Edition

Exercise 4. Variables and Names

Now you can print things with puts and you can do math. The next step is to learn about variables. In programming a variable is nothing more than a name for something, similar to how my name “Zed” is a name for, “The human who wrote this book.” Programmers use these variable names to make their code read more like English, and because they have lousy memories. If they didn’t use good names for things in their software, they’d get lost when they tried to read their code again.

If you get stuck with this exercise, remember the tricks you have been taught so far of finding differences and focusing on details:

1. Write a comment above each line explaining to yourself what it does in English.

2. Read your .rb file backward. ...