The Basics of Java Script

Arrays

Arrays allow you to ceate variables that are somewhat similar. For example, say you have a set of variables like the list below:

spoono1 = .5; spoono2 = 1; spoono3 = 1.5; spoono4 = 2; 95 more elements... spoono100 = 50;

As you can see the basic pattern is spoonox = x/2. Say I have 100 of these variables and I don't want to type 100 lines. I can use an array which looks like this (notice the first line, new should be all small letters, and the A in Array must be capitalized):

spoono = new Array for (x = 1; x <= 100; x = x +1); { spoono[x] = x/2}; This creates the array and individual variables can be called up using the following example syntax: spoono[50] = 25;

Events

Events tell Javascript when to be activated. For example in the Alerts Tutorial we had the alert box popup when the user clicked on a button. We used the onClick event so that an alert came up when the user clicked a button. So, here is a list of some other events and their uses in HTML coding:

Event	Function	HTML Use
onMouseOver	Activates Javascript when a user rolls his mouse over an object.	Used in links tags and used for animated buttons.
onMouseOut	Activates Javascript when a user rolls his mouse off of an object.	Used in links tags and used for animated buttons.
onClick	Activates Javascript when a user clicks something.	Used in links tags and forms (buttons, form fields, etc.)
onSubmit	Activates Javascript when a user presses the Submit button.	Used in forms.
onLoad	Activates Javascript when a page finishes loading.	Used in the body tag.
onUnload	Activates Javascript when a user leaves a page.	Used in the body tag.