Computers are almost everywhere today — from laptops, tablets, or phones, to TVs, watches, medical devices, kitchen appliances, cars, spaceships, big factories, little robots, and millions of other places large and small.
How do computers know what to do inside all these things? Someone has to teach them! Behind every cool animated movie, website, game, vehicle, or device, someone has worked hard to instruct a computer on how to perform its task. That person was a programmer.
In this chapter, I give you a little background about programming and how programmers organize their thoughts when writing computer software or code. I share some background about Ruby, the programming language I cover throughout this book. Then I tell you how to install the tools you’ll use for all the projects in the rest of the book.
What Is Programming?
Computers are kind of dumb by themselves. Without a person to tell it exactly what to do, a computer will just sit there. Everything a computer does — and I mean everything, from the display of pictures and text on a screen, to the understanding of what you type on a keyboard or touch and swipe on a tablet — requires some software to interpret signals coming through the various circuits in one part of the computer and modify and send them to the right place in another part to get something done. That’s a lot of work!
Fortunately, over the years, many smart people have come up with different ways to communicate clearly with computers. Writing instructions for a computer is called programming or coding, and the end result is a program or software.
A computer programming language shares many similarities to a human language. It has symbols and words (like nouns and verbs) that you put together following a syntax (rules for spelling, order, and punctuation).
When you start learning to program, you open up a wide world in which you can apply this knowledge when working with any technology that uses computers. You’ll be able to read other people’s programs to learn more about computers or to use code you write to solve homework problems, create puzzles, build a new game, create a website, or even control machines like robots.
Programs needs to be very precise in order to instruct a computer to do something. Imagine that you want to tell your friend to do something. For instance, how would you tell someone to sit down in a desk chair? You might say:
- Pull the chair out.
- Sit down.
Your friend is smart enough that your instructions make perfect sense, and she’ll sit on the chair safely without falling over or anything crazy like that. People have a lot of knowledge they can use to interpret instructions like this.
Now, if you have to tell a computer to sit down, what would that be like? You have to be a lot more exact. For example, you would have to say:
- Pull the chair away from the desk.
- Walk around so your body is in front of the chair.
- Turn ...
