Programming With Javascript

Before you learn how to read and write the JavaScript language itself, you need to become familiar with some key concepts in computer programming. They will be covered in three sections:

• A What is a script and how do I create one?
• B How do computers fit in with the world around them?
• C How do I write a script for a web page?

WRITING A SCRIPT

• To write a script, you need to first state your goal and then list the tasks that need to be completed in order to achieve it.

Humans can achieve complex goals without thinking about them too much, for example you might be able to drive a car, cook breakfast, or send an email without a set of detailed instructions. But the first time we do these things they can seem daunting. Therefore, when learning a new skill, we often break it down into smaller tasks, and learn one of these at a time. With experience these individual tasks grow familiar and seem simpler. Some of the scripts you will be reading or writing when you have finished this book will be quite complicated and might look intimidating at first. However, a script is just a series of short instructions, each of which is performed in order to solve the problem in hand. This is why creating a script is like writing a recipe or manual that allows a computer to solve a puzzle one step at a time. It is worth noting, however, that a computer doesn’t learn how to perform tasks like you or I might; it needs to follow instructions every time it performs the task. So a program must give the computer enough detail to perform the task as if every time were its first time.