how to defer parsing of javascript

Defer and async features are believed to be "familiar and unfamiliar" to many JavaScript developers, with two features that, literally, are well understood, respectively, as "deferred scripts" and "Asynchronous scripts". However, in the case of

The defer and async features are believed to be familiar to many JavaScript Developers & quot; but not familiar with & quot;. Literally, the two features are well understood; the functions of latency scripts & quot; and & quot; asynchronous scripts &

Our commonly used script tag has two attributes related to performance and JS file download and execution: Defer and async. Description of defer [from https://developer.mozilla.org/en/html/element/script] This Boolean attribute is set to indicate to

First of all, take a look at these three words: Without defer or async, the browser will immediately load and execute the specified script, "immediate" means before the document element that is rendered under the script tag, that is,

Javascript has the blocking feature. When a Browser executes Javascript code, it cannot do other things at the same time. When downloading JavaScript, all browsers will block all other activities, such as downloading other resources, content

In the Site page, usually need to introduce external JS resources, but external JS resources may cause DOM blocking, affecting the speed of page loading. By asynchronous or delay the execution of JS, you can refer to the external JS resources

Always write code when the common habit is that all the JS file directly loaded in the document's head tag, in the writing JS file sometimes to get some file objects when the empty object, this is because the document structure has not been loaded,

ArticleDirectory Async-HTML code Defer-HTML code Async & defer-what are their differences? Which browsers currently support defer and async? 1. No defer or async attributes 2. All are given the defer attribute. 3. partial

Original address: html5′s async Script AttributeOriginal date: September 22, 2010Translation Date: August 22, 2013 (Translator note: Asynchronous loading can be understood as non-blocking concurrency processing.) (Translator Note: the recommended

(Translator note: Asynchronous loading, can be understood as non-blocking concurrency processing.)(Translator's note: defer is recommended, but tested to find that the defer attribute is not valid for script within the page, there is no timing