Question

This you will find an example :

<div id="first_div">First Div<div>
<div id="second_div">Second Div<div>

$('#first_div').show().delay(2000).fadeOut(300);
$('#second_div').show().delay(2000).hide();

as you can see, fadeOut() is called after 2 seconds; hide() is called immediatly. Why? hide() doesnt wait delay() function.

Answer 1

From Jquery Delay

Added to jQuery in version 1.4, the .delay() method allows us to delay
the execution of functions that follow it in the queue. It can be used
with the standard effects queue or with a custom queue. Only
subsequent events in a queue are delayed; for example this will not
delay the no-arguments forms of .show() or .hide() which do not use
the effects queue.

Basically, fadeOut uses effects queue and hence is delayed. But show(), hide() don’t follow any queue