We often see the callback function in our studies. This article will explain in detail how to use the callback function Callback.
jQuery Problems with animation
Many jQuery functions involve animation. These functions may take speed or duration as optional parameters.
Example:
$("p").hide("slow")
The speed or duration parameter can be set to many different values, such as "slow", "fast", "normal" or milliseconds.
Example
$("button").click(function(){ $("p").hide(1000); });
Since JavaScript statements (instructions) are executed one by one - in order, the statements after the animation may generate errors or page conflicts because the animation has not yet Finish.
To avoid this situation, you can add the Callback function in the form of parameters.
jQuery Callback function
When the animation is 100% complete, the Callback function is called.
Typical syntax:
$(selector).hide(speed,callback)
The callback parameter is a function that is executed after the hide operation is completed.
Error (no callback)
$("p").hide(1000); alert("The paragraph is now hidden");
Correct (with callback)
$("p").hide(1000,function(){ alert("The paragraph is now hidden"); });
This article explains some usage of the callback function callback. I want to learn more about this. For knowledge, please pay attention to php Chinese website.
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