问题
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?
回答1:
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
回答2:
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