What is JavaScript?
* JavaScript was designed to add interactivity to HTML pages
* JavaScript is a scripting language (a scripting language is a lightweight programming language)
* A JavaScript consists of lines of executable computer code
* A JavaScript is usually embedded directly into HTML pages
* JavaScript is an interpreted language (means that scripts execute without preliminary compilation)
* Everyone can use JavaScript without purchasing a license
Are Java and JavaScript the Same?
NO!
Java and JavaScript are two completely different languages in both concept and design!
Java (developed by Sun Microsystems) is a powerful and much more complex programming language – in the same category as C and C++.
What can a JavaScript Do?
* JavaScript gives HTML designers a programming tool – HTML authors are normally not programmers, but JavaScript is a scripting language with a very simple syntax! Almost anyone can put small “snippets” of code into their HTML pages
* JavaScript can put dynamic text into an HTML page – A JavaScript statement like this: document.write(“<h1>" + name + "</h1>”) can write a variable text into an HTML page
* JavaScript can react to events – A JavaScript can be set to execute when something happens, like when a page has finished loading or when a user clicks on an HTML element
* JavaScript can read and write HTML elements – A JavaScript can read and change the content of an HTML element
* JavaScript can be used to validate data – A JavaScript can be used to validate form data before it is submitted to a server. This saves the server from extra processing
* JavaScript can be used to detect the visitor’s browser – A JavaScript can be used to detect the visitor’s browser, and – depending on the browser – load another page specifically designed for that browser
* JavaScript can be used to create cookies – A JavaScript can be used to store and retrieve information on the visitor’s computer
