webpack的exract-text-webpack-plugin插件的疑问

Question

刚学习webpack，请问注释行的代码是什么意思，查了官方文档没看明白。官方实例：Multiple Instances There is also an extract function on the instance.You should use this if you have more than one instance of ExtractTextPlugin.这是官方对extract方法的参数说明：extractExtractTextPlugin.extract(options: loader | object)Creates an extracting loader from an existing loader. Supports loaders of type { loader: [name]-loader -> {String}, options: {} -> {Object} }.options.use Loader(s) that should be used for converting the resource to a CSS exporting module (required)options.fallback loader(e.g 'style-loader') that should be used when the CSS is not extracted (i.e. in an additional chunk when allChunks: false)options.publicPathOverride the publicPath setting for this loader

Answer 1

你这是webpack1.x吧？ 
首先webpack在页面中引用某css比如require("a.css")； 如果没有配置项的话是css in js形式，
如果配置了style-loader是可以把css文件提取到style标签里边然后添加到head标签内的，如果在此之上配置了ExtractTextPlugin插件，就可以把这样式提取到文件中，不知道LZ了解了吗，毕竟单纯的理论有些晦涩(less sass等同理，只是多了一些配置)？