JS lazy loading speed up page opening sample code

First, JS lazy loading

The code is as follows:

Copy the codeThe code is as follows:

 
<script language="JavaScript" src="" ></script> 
<script language="JavaScript"> 
setTimeout("('my').src='include/...file...php'; ",3000);//Delay 3 seconds
</script> 

Second, JS finally loaded

Insert the following code where you need to insert JS:

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

Of course, that LOADING...you can change it to a small picture you like. It looks very AJAX effect.

Then insert at the bottom of the page:

Copy the codeThe code is as follows:

 
<SPAN class=spanclass id=AD_L4EVER> 
Your JS code is here!</SPAN>
<script>=AD_L4EVER.innerHTML;AD_L4EVER.innerHTML="";</script> 

Third, JS finally loaded

Where to display ads
<div ></div>

Ad content you want to display

Copy the codeThe code is as follows:

 
<div  style="display:none"> 
<script language="javascript" src="/include/.......js"></script> 
</div> 

Determine whether the ad position to be displayed exists

Copy the codeThe code is as follows:

 
<script language="javascript"> 
function chkdiv(divid){ 
var chkid=(divid); 
if(chkid != null) 
{return true; } 
else 
{return false; } 
} Finally, the ad is displayed
if (chkdiv('guangg1')) { 
('guangg1').innerHTML= ('ggad1').innerHTML; 
('ggad1').innerHTML=""; 
} 
</script> 

setTimeout usage

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

Here we focus on remembering that the first parameter is a function call, assuming it is a function.

1. Function has no parameters:

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

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

When the first parameter is added with quotes, delay by one second:
setTimeout("alertV()",1000);

2. The function has parameters:

function alertV(event){ alert("keyCode="+); }

At this time, it should be set to:
setTimeout(function(){alertV(event);},1000); otherwise, the parameter will be not defined.