A few things you should know

One of the best things about JavaScript is that you can do a great deal with very little programming. You don't need a fancy computer, you don't need any software other than a word processor and a Web browser, and you don't need access to a Web server; you can do all your work right on your own computer.

Even though it's simple to work with, JavaScript is a complete programming language, so as you learn more complicated JavaScript, you're also learning the basics of computer programming. If you want to move on to other programming languages, like Perl, C, C++, or Java, JavaScript is a great introduction.

As you learn JavaScript, you'll discover that much of it is very logical and easy to figure out when you think about it carefully. There are however a few features of JavaScript that can be a little confusing and simply must be memorized.

Here's a few of the most important ones.

Almost all numbered lists in JavaScript begin with zero, instead of one.

As you become more experienced with programming, this might actually start to make sense. But at first, you're likely to find it confusing. For example, suppose you want to change the content of the first text input box on your page. Don't think of it as text input number 1, think of it as text input number 0.

There are two types of quotation marks in JavaScript.

Quotation marks are used frequently in JavaScript to indicate that a line of text should be treated as text and not as code. These lines of text are often referred to as "text strings." You can indicate a text string either by using double quotes ("text") or by using single quotes ('text'). If you start a text string with one kind of quotation mark, you have to finish it with the same kind. It's necessary to use different types of quotation marks if you embed one text string inside another text string.

JavaScript is case-sensitive, HTML is not.

If you've worked a lot with HTML, you're used to the fact that you can use lower case and capitol letters interchangeably. For example, the tag <body> is the same as <BODY>. In fact you can even write <BoDy> if you like. But in JavaScript, this is not the case, you can only spell things one way. So pay close attention to capitol letters. If your code isn't working, this is one of the first things you should check.

I encourage you to look at the JavaScript that's contained in many of the pages of this course. Just use your browser's View Source menu command to see it. It's also a good idea to look at the source code of any page that seems to be doing something interesting with JavaScript. It's the best way to learn.

On occasion, there will be material that you encounter in the examples that hasn't been covered in the course yet. This is necessary in order to create interesting examples. When I include techniques that haven't been explained yet, I'll point it out so you don't end up wasting a bunch of time trying to figure them out.