What are queues in jQuery?

Question

I found the jQuery.com document on queue()/dequeue() is too simple to understand. What exactly are queues in jQuery? How should I use them?

Answer 1

It allows you to queue up animations... for example, instead of this

$('#my-element').animate( { opacity: 0.2, width: '100px' }, 2000);

Which fades the element and makes the width 100 px at the same time. Using the queue allows you to stage the animations. So one finishes after the other.

$("#show").click(function () {
    var n = $("div").queue("fx");
    $("span").text("Queue length is: " + n.length);
});

function runIt() {
    $("div").show("slow");
    $("div").animate({left:'+=200'},2000);
    $("div").slideToggle(1000);
    $("div").slideToggle("fast");
    $("div").animate({left:'-=200'},1500);
    $("div").hide("slow");
    $("div").show(1200);
    $("div").slideUp("normal", runIt);
}
runIt();

Example from http://docs.jquery.com/Effects/queue