JavaScript Overview Developer Essentials How to Code Language Constructs The DOM concept- API, (use W3C model) Objects –properties Methods Events Applications; –Rollovers –Smart Forms –Cookies

Overview A programming Language that adds interactivity to Web Pages –a scripting language A JS script is a program that is included in an HTML page A JS script is interpreted by Web browsers Related Scripting Languages –VbBasic, ActionScript:Flash, Adobe :JScript, Mac &.NET

Background Used to be “Live Script” –Plus more! What can JavaScript do Create an active user interface Validate user input on Forms Create HTML pages on the fly Control Web Browsers

Can’t do Talk to databases Write to files Keep a counter or Track of State!

Applications We use JavaScript for: Tailoring the experience –Different content based on criteria Extending the experience –Dynamic pages –User interface elements eg; pop-up menus Validating input –Pre processing forms

JScript Language Characteristics –where to place code –statements Programming Concepts –Sequence –Selection –Iteration Server side vs Client side

JS- Statements Invoke Object Methods Initialise or Define Variables Manipulate Variables Invoke a Function Make Programming Decisions

JS- Statements cont. When the HTML Document Loads Immediately after the Doc Loads Respond to USER Action –Event Handler When invoked by other Script Statements

JS- example My First JavaScript Script.highlight {font-weight: bold} Let the Scripting begin <!-- hide script form old browsers document.write(“This browser version” + navigator.appVersion); document.write(“of ” + navigator.appName + “.”); //end the script hiding -- >