Аннотация

This is a book about instructing computers. Computers are about as common as screwdrivers today, but they are quite a bit more complex, and making them do what you want them to do isn’t always easy.
    If the task you have for your computer is a common, well-understood one, such as showing you your email or acting like a calculator, you can open the appropriate application and get to work. But for unique or open-ended tasks, there often is no appropriate application.
    That is where programming may come in. Programming is the act of constructing a program—a set of precise instructions telling a computer what to do. Because computers are dumb, pedantic beasts, programming is fundamentally tedious and frustrating.
    Fortunately, if you can get over that fact—and maybe even enjoy the rigor of thinking in terms that dumb machines can deal with—programming can be rewarding. It allows you to do things in seconds that would take forever by hand. It is a way to make your computer tool do things that it couldn’t do before. On top of that, it makes for a wonderful game of puzzle solving and abstract thinking.
    Most programming is done with programming languages. A programming language is an artificially constructed language used to instruct computers. It is interesting that the most effective way we’ve found to communicate with a computer borrows so heavily from the way we communicate with each other. Like human languages, computer languages allow words and phrases to be combined in new ways, making it possible to express ever new concepts.
    At one point, language-based interfaces, such as the BASIC and DOS prompts of the 1980s and 1990s, were the main method of interacting with computers. For routine computer use, these have largely been replaced with visual interfaces, which are easier to learn but offer less freedom. But if you know where to look, the languages are still there. One of them, JavaScript, is built into every modern web browser—and is thus available on almost every device.
    This book will try to make you familiar enough with this language to do useful and amusing things with it.