How do I set the load and execution order of two external async Javascript files?
Given the following...
<script src="framework.js" async></script> // Larger file
<script src="scripts.js" async></script> // Small file
Though second in order scripts.js is downloading and executing before framework.js due to it's file size, but scripts.js is dependent on framework.js.
Is there a way natively to specify the load and execution order whilst still maintaining async properties?
You want to use defer if you want to preserve the execution order. What defer does is it async downloads the script, but defers execution till html parsing is done.
<script src="framework.js" defer></script>
<script src="scripts.js" defer></script>
However, you may want to start creating custom bundles once the number of scripts go higher.
You can see the difference here
If you need solution for IE9 (that not support defer attribute), I have created a small loader script:
https://github.com/mudroljub/js-async-loader
In short, it loads all your scripts asynchronously, and then executes them consequently.
来源：https://stackoverflow.com/questions/28893519/any-way-to-control-javascript-async-load-order