Only IE does not support the third or more parameters of the setTimeout/setInterval function

Only IE does not support the third or more parameters of the setTimeout/setInterval function_javascript tips

WBOY

Release： 2016-05-16 18:06:20

Original

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Copy code The code is as follows:

 
setTimeout(function(obj){ 
alert(obj.a ); 
}, 2000, {a:1}); 

The third parameter is passed, and the third parameter will be passed in as the parameter obj of the callback function. 1 pops up in non-IE browsers. This has the advantage that it solves the execution context of the callback function. For example, if you want to call a method of an object, you can pass the object in through parameters.

Copy code The code is as follows:

 
setTimeout(function(obj){ 
obj. method(); 
}, 2000, obj); 

Of course, you can also pass multiple parameters to the callback function, as follows

Copy code The code is as follows:

 
setTimeout(function(a, b){ 
alert(a); 
alert(b); 
}, 2000, 1,2); 

This time we passed two parameters 1,2 to the callback function, and 1,2 popped up in Firefox/Safari/Chrome/Opera in turn . You can send more if you want.

Although IE does not support the third parameter, there are still differences between Firefox and Safari/Chrome/Opera

Copy code The code is as follows:

 
setTimeout(function(){ 
alert(arguments.length); 
}, 2000, 1,2); 
 

Pass two parameters 1 and 2 to the callback function, and then alert the length of the actual parameters
Firefox: 3
Safari/Chrome/Opera: 2
It’s strange, it’s clearly passed There are two parameters, but the one that pops up in Firefox is 3. If you output the third parameter, you will find that it is a number, sometimes negative.
Close:

http://www.w3.org/TR/Window/

https://developer.mozilla.org/en/DOM/window.setTimeout

http://msdn.microsoft.com/en-us/library/ms536753(v=vs.85).aspx
//Solve the bug of setTimeout parameter passing under IE

Copy code The code is as follows:

 
//Solve the bug of setTimeout parameter passing under IE 
if (! [1,]) { 
(function(overrideFun){ 
window.setTimeout = overrideFun(window.setTimeout); 
window.setInterval = overrideFun(window.setInterval); 
}) ( 
function(originalFun){ 
return function(code, delay){ 
var args = [].slice.call(arguments, 2); 
return originalFun( 
function() { 
if (typeof code == 'string') { 
eval(code); 
} 
else { 
code.apply(this, args); 
} 
}, 
delay 
) 
} 
} 
); 
} 