jQuery: adding change event handler with predefined function

问题

So I have the following:

var change_handler = function(element) {
    // ... do some fancy stuff ...
}

Now, I want to attach this to an element. Which is the better/best or more correct method?

$('element_selector').change(change_handler(this));

Or...

$('element_selector').change(function() { change_handler(this); });

And does it make any difference if you're passing the object to the function or not?

回答1:

Neither..

$('element_selector').change(change_handler);

change_handler will be the so to speak pointer to the method and the argument of the element is already passed by jQuery

If you were to use $('element_selector').change(change_handler(this)); it wouldn't actually assign the method as the handler but rather run the method and attempt to assign the result as the handler, the other option is superfluous because you can use the method name as described above instead of re-wrapping the method.

回答2:

This is another way to approach the problem given by the OP... partial function application a la another SO Q. Bind the change handler with the arg of interest and pass the resulting partial as the arg to the change handler:

var myChangeHandler = partial(change_handler, this);
$('element_selector').change(myChangeHandler);

来源：https://stackoverflow.com/questions/4524207/jquery-adding-change-event-handler-with-predefined-function