BOM overview

One . What is? BOM

BOM( Browser Object Model) Browser object model , It provides objects that interact with browser windows independently of content , Its core object is window.
BOM It consists of a series of related objects , And each object provides many methods and properties .
BOM Lack of standards ,JavaScript The standard organization of grammar is ECMA,DOM Our standardization organization is W3C,BOM Initially Netscape Part of the browser standard .
 

Two .BOM and DOM The difference between

DOM

Document object model

DOM Is to put 「 file 」 As a 「 object 」 To look at

DOM The top-level object of is document

DOM The main learning is to operate the page elements ·

DOM yes W3C Standard specification

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BOM

Browser object model

hold 「 browser 」 As a 「 object 」 To look at

BOM The top-level object of is window

BOM Learn some objects that interact with the browser window

BOM It is defined by browser manufacturers on their respective browsers , Poor compatibility

3、 ... and .BOM The composition of the

BOM Than DOM Bigger ,BOM contain DOM

 

window Object is the top-level object of the browser , It has a dual role .

1. It is JS An interface for accessing browser windows .
2, It's a global object . Variables defined in the global scope 、 Functions will become window Properties and methods of objects .
You can omit... When calling window, The previous dialog boxes belong to window Object methods , Such as alert)、prompt() etc. .
Be careful :window One of the special properties of the following window.name