JS lazy load to speed up the page opening sample code

  • 2020-03-30 01:08:00
  • OfStack

First, JS lazy loading

The code is as follows:
<script language="JavaScript" src="" id="my"></script> 
<script language="JavaScript"> 
setTimeout("document.getElementById('my').src='include/... file ...php'; ",3000);//Delay 3 seconds

Second,JS loads last

Where JS needs to be inserted, insert the following code:

< SPAN id = L4EVER > LOADING... < / SPAN>

Sure, that LOADING... You can change it to your favorite small picture. It looks very AJAX.

Insert at the bottom of the page:
<SPAN class=spanclass id=AD_L4EVER> 
 your JS Here's the code !</SPAN> 

Third,JS loads last

Want to show the location of the AD
< Div id = "guangg1" > < / div>

The content of the AD you want to display
<div id="ggad1" style="display:none"> 
<script language="javascript" src="/include/.......js"></script> 

Determine whether the advertising location to be displayed exists
<script language="javascript"> 
function chkdiv(divid){ 
var chkid=document.getElementById(divid); 
if(chkid != null) 
{return true; } 
{return false; } 
}  Finally, display ads  
if (chkdiv('guangg1')) { 
document.getElementById('guangg1').innerHTML= document.getElementById('ggad1').innerHTML; 

SetTimeout usage

The standard syntax for setTimeout is: setTimeout(expression, time (milliseconds)) with two parameters.

Note here that the first argument is a function call, assuming a function.

1. The function has no parameters:

The function alertV () {alert (" 000 "); }

When the first parameter is not quoted ("" or "), delay by one second:
SetTimeout (alertV, 1000);

When the first parameter is quoted, delay by one second:
SetTimeout (alertV "()", 1000);

2. Function has parameters:

Function alertV (event) {alert (" keyCode = "+ event. KeyCode); }

This should be set to:
SetTimeout (function () {alertV (event); }, 1000); Otherwise the parameter is not defined.

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