JavaScript/JavaScript within HTML: Difference between revisions

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With the example <pre><code><script src="https://example.com/dist/js/externallib.min.js"></script></code></pre> you can inject remotely maintained code from the server <pre>https://example.com</pre> in your local web project. Remote code updates may break your local project or unwanted code features may be injected ininto your web project. On the other hand, centralized maintained and updated libraries serve your project due to bugfixes that are automatically updated in your project when the library is fetched again from the remote server.

Minified Javascript code compresses the source code e.g. by shorting comprehensive variables like <tt>vImage</tt> into a single character variable <tt>a</tt>. This reduces significantly the size of the library and therefore reduces network traffic and response time of until the web page is ready. For developementdevelopment and learning it might be helpful to have the uncompressed libraries locally available.

The <code>script</code> element may appear almost anywhere within the HTML file. But there are, however, some best practices for speeding up a website <ref>Yahoo: [http://developer.yahoo.com/performance/rules.html Best practices for speeding up your website]</ref>. Some people suggest to locate it just before the closing <code></body></code> tag. This speeds up downloading, and also allows for direct manipulation of the Document Object Model (DOM) while it is rendered. But a similar behavior is initiated by the above -described <code>async</code> and <code>defer</code> attributes.