BOM browser object model

BOM：Browser Object Model（ Browser object model ）

Provides objects that interact with browser windows independently of content

Object name explain

window Window object , It can be used to control the current window , Or open a new window

screen Screen objects , Get screen related information

 navigator Browser object , This object can be used to determine the browser used by the user

 

history Historical object , It can be used to move forward or backward a page , There must be one a link , To jump , Generate records

 //history.forward(); history.go(1)// Browser forward ;

history.go(2)// Browser jumps to the third page , But the second page must jump to the third page and be effective only after it is recorded

 //history.back();history.go(-1)// Browser back ;

 //history.go(0)// Refresh the page ;

 window.location object

Used to get the address of the current page (URL), And redirect the browser to a new page

grammar explain

location.href Return to... On the current page URL, Full address

location.href="./xxx.html", Quotation marks must be added

location.pathname return URL Pathname of

location.assign Load new document , Jump

location.assign（“./xxx.html ”）

location.hosthost Address （ Include domain name （ only one ） And port （ Can be more ））

location.hostname    domain name

location.origin  source address ： Include （ agreement ：http:// perhaps https:// encryption ）、 Domain name and port

location. prort port

location.protocol  agreement ：http:// perhaps https:// encryption

location.hash Get hash address Anchor link address name

location. search  Search data , Get string type   

notes ： A general anchor address is placed behind the search data

location.reload Reload And history.go(0)  The function of refreshing the page is the same

location.replace Replace the current page , No history will be generated

JavaScript Timing events

grammar explain

setInterval() Executes the specified code continuously for the specified number of milliseconds in the interval

clearInterval() Used to stop setInterval() Function code executed by method

setTimeout() Pauses for the specified number of milliseconds before executing the specified code

clearTimeout() Used to stop execution setTimeout() Method

setInterval() Method Timer , Call a function repeatedly , There is a fixed time interval between each call

setInterval(" Called function ", The number of milliseconds between )

// setInterval After execution, a unique Id,Id Is the key to clearing the timer

clearInterval() Method Clear the timer

Clear the timer

clearInterval(setInterval() Back to ID value )

for example ：

setTimeout() Method   Time delayer , When the appointed time comes , Will execute the function once , No more repetition

setTimeout(" Called function ", The number of milliseconds to wait )

example ：

3 second (3000 millisecond ) Then execute the function a() once

a=setTimeout(function(){

//do something

},3000)

clearTimeout() Method Clear the delayer

clearTimeout(setTimeOut() Back to ID value )

clearTimeout() Method can be cancelled by setTimeout() Method execution

setInterval() And setTimeout、clearInterval()、clearTimeout() All belong to window Object

setInterval() And setTimeout Features and differences ：

characteristic

setInterval() and setTimeout() Used to handle delayed and scheduled tasks ,

difference

setTimeout() Method is used to call functions or compute expressions after specified milliseconds. , and setInterval() You can call a function or expression every specified number of milliseconds

practice 1： Real time computing from now to 2022 year 7 month 1 Countdown to the Japanese army day , The format is... Before the army day ：xx God xx Hours xx minute xx second , And in a second , Print on the page once , After a second , Print on the page once .

localStorage

localStorage   Permanent storage , Even if the browser closes the page , Data is still stored locally , Unless you clear it yourself

// * As long as the domain name and port are consistent , Although the path names are different , But the data still exists