BOM document

1.BOM The concept of

BOM(Browser Object Model) The browser object model , The browser object model provides content independent 、 Object structure that can interact with browser windows .BOM Composed of multiple objects , Which represents the browser window Window The object is BOM The top object of , Other objects are children of the object .

2.BOM The top object of window, When calling window Properties and methods under can be omitted window.

3. Page load event

onload attribute

window.onload = function () {
    //  When the page is loaded, execute 
    //  When the page is fully loaded （ Include images 、 Script files 、CSS  Documents, etc. ） perform 
}

onunload attribute

window.onunload = function () {
    //  Execute... When the user exits the page 
}

4. Timer

setTimeout() and clearTimeout()

Executes the specified function after the specified number of milliseconds , Only once .

 

//  Create a timer ,1000 In milliseconds, execute , Return to the mark of the timer 
var timerId = setTimeout(function () {
    console.log('Hello World');
}, 1000);

//  Cancel the timer 
clearTimeout(timerId);

setInterval() and clearInterval()

Functions that are called regularly , At a given time ( Unit millisecond ) Call the function periodically

 

//  Create a timer , every other 1 One call per second 
var timerId = setInterval(function () {
var date = new Date();
    console.log(date.toLocaleTimeString());
}, 1000);

//  Cancel the timer 
clearInterval(timerId);

5.location object

location The object is window Object , Time can be omitted window object

location Can get or set the browser address bar URL

6.URL

Uniform resource locator (Uniform Resource Locator, URL)

URL The composition of

scheme://host:port/path?query#fragment

scheme: Communication protocol

frequently-used http,ftp,maito etc.

host: host

The server ( Computer ) The domain name system (DNS) Host name or IP Address .

port: Port number

Integers , Optional , Use the default port of the scheme when omitted , Such as http The default port is 80.

path: route

By zero or more '/' String separated by symbols , Generally used to represent a directory or file address on the host .

query: Inquire about

Optional , Used to pass parameters to dynamic web pages , There can be multiple parameters , use '&' Symbols separate , The name and value of each parameter are '=' Symbols separate . for example ：name=zs

fragment: Pieces of information

character string , Anchor point .

location Who are the members ？

Use chrome The console view

assign()/reload()/replace()

hash/host/hostname/search/href……

7.history object

back()

forward()

go()

8.navigator object

userAgent

adopt userAgent You can determine the type of user's browser

platform

adopt platform You can judge the system platform type of the browser