JavaScript basic Syntax (v)

BOM Browser Object Model

A BOM (browser object Model) that provides objects that interact with a browser window.

first, window Object

The Window object represents the entire browser window.

Window objects are supported by all Browsers. It represents a browser window.

All JavaScript global objects, functions, and variables automatically become members of the window Object.

A global variable is a property of a window Object.

A global function is a method of a window Object.

Even the document of the HTML DOM is one of the properties of the window Object.

(1). System message box alert ()

Example: Alert (' Hello ');

(2). Confirmation dialog box confirm ()

The method returns a Boolean value, and if clicked OK returns true, Click Cancel to return false;

Example: if (confirm ("ok to Delete?")) {

Delete

}

(3). Input dialog box prompt ()

If you click OK to return the value in the text box as a function value, click Cancel to return null

example: var name = prompt ("please Enter your Name?") ","");

If (name! = Null) {

Alert (' Welcome ' + name);

}

(4). Open a new window window.open ()

Cases:

window.open ("http://www.baidu.com", "_blank", "width=500, height=500");

Note: to remove the browser blocking Feature.

(5). Timer

A, Window.setinterval (); Setting the loop Timer

The SetInterval () method invokes a function or evaluates an expression according to the specified period (in milliseconds).

SetInterval (code,millisec,lang)

Parameters	Describe
Code	Necessary. The function to invoke or the code string to Execute.
Millisec	Have to. The time interval, in milliseconds, between periodically executing or calling Code. Note: 1000ms=1s
Lang	Optional. JScript | VBScript | Javascript

B,window. Clearinterval (); Clear the Loop timer

C, Window.settimeout (); Set up a single time timer

D, window.cleartimeout () Clear a single time timer

Here's an example: setting a real-time clock

JS Code:

<script type= "text/javascript" >functiontime () {varMydate=NewDate (); varYear=Mydate.getfullyear (); Get the full yearvarMonth=Mydate.getmonth (); Get the current month (0-11, 0 for January)varday=mydate.getdate (); Get Current day (1-31)varhours=mydate.gethours (); Gets the current number of hours (0-23)varmin=mydate.getminutes (); Gets the current number of minutes (0-59)varSecond=Mydate.getseconds (); Gets the current number of seconds (0-59)

　　　　　　　　　var week=mydate.getday ();  Get current week (0-6,0 is Sunday)
　　　　　　　　  var weekday=[' Sunday ', ' Monday ', ' Tuesday ', ' Wednesday ', ' Thursday ', ' Friday ', ' Saturday '
　　　　　　　　  document.getElementById ("clock"). innerhtml= "now is:" +year+ "year" +month+ "month" +day+ "day" +hours+ ":" +min+ ":" + Second+
　　　　　　　　  window.setinterval ("time ()"), +//set timer with 1s timing.

</script>

HTML code:

<onload= "time ()">    <ID= "clock"></div></body>

The output is:

It should have been animated, but here is the Picture. You can copy the code to see the effect yourself.

Ii. history Object

The history object is a child object of the Window object , corresponding to the Browser's

Historical RECORDS.

History.back (); Same as clicking Back button in browser

History.forward ();//the Same as clicking the button in the browser

third, location Object

The location object is also a child of the Window object , which allows you to get or set the current address of the Browser.

1. Jump to another page

Window.location.href = "http://www.163.com";

Location.href = "http://www.163.com";

2. Reload page (refresh)

Location.reload ();

Iv. Navigator Object

The Navigator object contains information about the Web browser, which is also a property of the window and can be used

Window.navigator reference it, or you can use the Navigator reference

Example: get the browser internal code, name, operating system and other information

var info = navigator.useragent;

Alert (info);

JavaScript basic Syntax (v)