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

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
)
}
}
);
}