What is JavaScript?

JavaScript was created by Netscape Communications as a combination of Java and HTML. It is a scripting language that allows web pages to become more interactive. Unlike Java applets that have to be compiled first before being added to a page, JavaScript is interpretted by the browser and doesn't require any additional developing tools. When using JavaScript, all code must be placed in between the tags <SCRIPT> and </SCRIPT>. There are certain JavaScript commands that do not need to go between these tags (such as some of the mouse commands covered later).

This tutorial will cover how JavaScript can do some of the same things HTML can do such as writing text on the screen and setting the background color. Knowing some of these basics covered in the next several tutorials will allow you to write your own scripts.

We can write text using JavaScript by using document.write( ). The text to be written goes in ( ), and is enclosed in quotes. This is how it will look:

<SCRIPT>
document.write("Put text here")
</SCRIPT>

And here is how it will look on the screen:

We can combine HTML with JavaScript to change the appearance of the text. If we wanted to underline the text here is what our example would look like:

<SCRIPT>
document.write("<U>Put text here</U>")
</SCRIPT>

And here is what it will look like:

JavaScript can also be used to set the background color of the page. You can also use the idea to dynamically change the background color if a certain link or picture is clicked as described in the Mouse Commands Tutorial.

To do this we use document.bgColor="color". For a list of colors refer to the color chart. Here is what it will look like:

<SCRIPT>
document.bgColor="red"
</SCRIPT>

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