SetTimeout parameters [easy to understand]

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unction test(s)
{
    alert(s);
}
window.setTimeout(function(){test('str');},1000);

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That's it … Why is that so . because setTimeout The first parameter required is the function … such as setTimeout(a_fun,1000) This is OK ,a_fun It's a function . however setTimeout(a_fun(),1000); That won't work . Because here a_fun() It's actually the return value of the function … It should be clear in this way . in addition , It is not recommended that someone use the method on the Internet setTimeout(‘test(1)’,1000); Form like this , Because this is not practical in many cases . If you really want to use this method , Only such ：setTimeout(“test(‘”+param+”‘)”,100); This way, .

There's another way ：

function timeClick(obj)  
       {  
        //   var obj=document.getElementById('');  
           obj.style.backgroundColor="gray";  
           obj.onclick=function(){ return false;};  
           setTimeout(function(){resetbgColor(obj);},3000);  
       }  
         
       function resetbgColor(obj)  
       {  
         //  var obj=document.getElementById('');  
           obj.style.backgroundColor="";  
        //   $('#'+'').click(timeClick);  
      //  debugger;  
           obj.οnclick=function(){  
               timeClick(this);  
           };  
       }  

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I find this sentence is really omnipotent , I'm so impressed , function(){ method(param);}

Both of these places are used , Solved all my problems ,1.setTimeout The parameter 2. Dynamic setting onclick event

setTimeout(function(){resetbgColor(obj);},3000);

obj.οnclick=function(){ timeClick(this); };

There's another way ：

<script language="JavaScript" type="text/javascript">
<!--
var userName="jack";
// Display welcome information according to user name 
function hello(_name){
       alert("hello,"+_name);
}
// Create a function , Used to return a parameterless function 
function _hello(_name){
       return function(){
             hello(_name);
       }
}
window.setTimeout(_hello(userName),3000);
//-->
</script>

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this A function is defined in _hello, Used to receive a parameter , And return a function without parameters , The parameters of the external function are used inside this function , So as to call , You don't need to use parameters . stay window.setTimeout Function , Use _hello(userName) To return a function handle without parameters , Thus, the function of parameter transmission is realized .

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