jQuery

 Wrapper function

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A function that is executed once the page has been finished loading

$(function () { //all our code will be in here... })

Most jQuery code that we see in the wild resides within some kind of wrapper like this. Using $(function(){}); is a shortcut to jQuery's document.ready function, which is fired once the DOM for the page has loaded

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https://www.paulirish.com/2009/perf/

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window object is also known as the Global Namespace. The main concept of namespacing is to provide a way to logically group all the related pieces of a distinct and self-contained part of an application.