ES6 imports - what does the exclamation mark mean?

问题

I'm following along with the Choose ES6 Modules Today guide, and I noticed one of the import statements he's using has an exclamation mark at the end:

import 'bootstrap/css/bootstrap.css!';

What does that exclamation mark signify?

This import statement appears on the first line of the startup.js file.

回答1:

It means that a plugin will be called to load the file. By default the plugin/loader name equals the extension name. So in your example the css plugin will be called to load the bootstrap/css/bootstrap.css file. One can define the plugin explicitly:

import 'bootstrap/css/bootstrap.css!css';

or

import 'bootstrap/css/bootstrap.css!customCssLoader';

Plugins have to be installed like any other normal module. More about this syntax here.

来源：https://stackoverflow.com/questions/31620018/es6-imports-what-does-the-exclamation-mark-mean