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
Source link: http://www.w3schools.com/js/default.asp
相关文档：
1 一起困惑始于变量的作用域
请先看下面的代码：
示例1：
var message = " this is a very simple function ";
function simpleFunc(){
alert(message);
}
背后的道理大家都懂（如果不懂的可以先别往 ......
上回说到，操作Object Array
其实还可以这样操作：
var Room = [
{
ID: 'bot',
name: 'test' ......
< a href =
"#"
onClick =
"javascript:window.external.AddFavorite(document.URL,document.title);return
false"
rel=
"sidebar"
> 收藏本页 </ a >
取得当前页的URL: document.URL
取得当前页的title: document.title
实现在Firefox中“收
藏本� ......
var vKeyCode= e.getKeyCode();
if (vKeyCode >= 65 && vKeyCode <= 90 ) // Caps Lock 打开
{
......
