jQ30-Complete

jq30.js

//The POINTS

window.jQuery = window.$ = jQuery

using CSS selector or jQuery helper or jQuery method // $('li:first-child') vs. $('li':first) || $('li').first() 

this refferring the regular DOM node 
$(this) jQuery wrapped // jQuery methods can be used

use direct used JQ methods instead of refferred helper methods 
// .hover ==> .on('mouseenter', )
// .click ==> on.('click', function(){}) because earlier is refferring latter

CACHE Dom Querying if used multiple times // var $this = $(this); 

use CHAINING for not using same methods multiple times

STACK management // .end()  // .andSelf()

use EVENT DELEGATION,, attach event handler to the parent instead of every child element
also updated elements or newly generated elements will not have event handler attached if event is not delegated to a parent or if the parent was not covering new elements
// 	$('dl').on('mouseenter', 'dt', function(){ 

// - Avoid unnecessary iteration. Most jQuery methods provide "implicit
// iteration" -- they will operate on all of the elements in a selection.
// Additionally, many methods allow passing a function that will operate
// on each method in the selection.

use html5 // $(this).attr('data-file'); == $(this).data('file');  //unlimited custom attributes


parents =~ children
closest =~ find

append  ~ prepend ~    after ~      before          (working with existing element)
appenTo ~ prependTo ~ insertAfter ~ insertBefore    (IF you are CREATING the element) 

//var co = $('span.co').each(function(){
var co = $('article').find('span.co').each(function(){ // => parent.find ==> better performance