The Basics

You have already seen the mandatory Hello World program - so no need to repeat that here. From now one we will be concentrating one stuff inside the script tag. So when I say
alert("Hello World")
I mean the full html file with the 'alert("Hello World")' text inside the script tag. But if you want to try the code in the T-Box, you just have to type alert("Hello World") and not the full Html content.

Wondering how to write a the string to the HTML area in the window rather than pop up a message box? This code will do the trick.

document.write("Hello World")

Be careful with this. Put it after the the <body> tag like this

</head> <body> <script language="javascript"> document.write("Hello World") </script> ...

If it is given before the body tag, a new page will be created with the 'Hello World' text. This will not work with the T-Box. T-Box will make a new page with the given text. Try it out if you must. Just click the 'Back' button to come back.

Comments

Comment is what a programmer will enter into the source code to make the source more understandable. They are ignored by the interpreter. It is a good idea to explain what you are doing using comments - this makes the code more readable.

There is two types of comments in JavaScript...
// - The Line Comment
/* */ - Block Comment

Example

//This is a single line comment
/* This is a block comment. 
This will comment out every 
thing from the beginning
to the end */

Semi-colon

Semi-colons are not a must but it can be used to separate multiple statements on the same line.

Example

i=0;i++;

Previous
HTML and JavaScript

Contents

Next
Dialogs