js-BOM

brief introduction

BOM： Browser object model （Browser Object Model）

Provides content independent , Object structure that can interact with browser windows

Can realize the function

1. Pop up a new browser window

2. Move , Close and resize browser windows

3. Page forward and backward

window object

Common properties

history

Window.history Is a read-only property , No assignment exists

About customer visits URL Information about

location

About the current URL Information about

window.location="http://www.baidu.com";

Common methods

Direct use , Unwanted .

Method name	say bright
prompt( )	Displays a dialog box that prompts for user input
alert( )	Display a warning box with a prompt and a OK button
confirm( )	Display a prompt message 、 Dialog for OK and Cancel buttons
close( )	Close the browser window
open( )	Open a new browser window , Load given URL Specified document
setTimeout( )	Call the function or computing expression after the specified millisecond count.
setInterval( )	According to the specified period （ In milliseconds ） To call a function or expression

history object

Need to use window.history To get

Common methods

name	say bright
back()	load history Previous in object list URL
forward()	load history Next in object list URL
go()	load history A specific object in the object list URL

location object

Need to use window.location To get

Common properties

name	say bright
host	Set or return the host name and current URL Port number
hostname	Set or return to current URL The host name
href	Set or return to full URL

Common methods

name	say bright
reload()	Reload current document
replace()	Replace the current document with a new document

window.location.replace("https://www.baidu.com");

js Built-in objects

Array

String

Math

Method	say bright	Example
ceil()	Round up logarithm	Math.ceil**(25.5); return 26Math.ceil(-25.5); return -25**
floor()	The logarithm is rounded down	Math.floor(25.5); return 25Math.floor(-25.5); return -26
round()	Round a number to the nearest number	Math.round(25.5); return 26Math.round(-25.5); return -26
random()	return 0~1 Random number between	Math.random**(); for example ：0.6273608814137365**

// return 2~99 The random number 
var iNum=Math.floor(Math.random()*98+2)

Date

var  today=new Date();   // Returns the current date and time 
var tdate=new Date("september 1,2013,14:58:12")

Common methods

Method	say bright
getDate**()**	return Date Every day of the month of the object , Its value is between 1～31 Between
getDay**()**	return Date Every day of the subject's week , Its value is between 0～6 Between
getHours**()**	return Date Hours of objects , Its value is between 0～23 Between
getMinutes**()**	return Date Minutes of objects , Its value is between 0～59 Between
getSeconds**()**	return Date The number of seconds of the object , Its value is between 0～59 Between
getMonth()	return Date Month of object , Its value is between 0～11 Between , January is 0
getFullYear()	return Date Year of object , Its value is 4 digit
getTime()	Back from a moment （1970 year 1 month 1 Japan ） Milliseconds since

Timing function

setTimeout()

function timer(){ 
    
        var t=setTimeout("alert('3 seconds')",3000);
}
//3 Once per second 

setinterval()

var  myTime＝setInterval("disptime() ", 1000 );

Clear function

clearTimeout()

 var t=setTimeout("alert('3 seconds')",3000);
clearTimeout(t);

clearInterval ()

var  myTime＝setInterval("disptime() ", 1000 );
clearInterval(myTime);