babel-polyfill没有转码？

Question

.babelrc{"presets":["es2015","stage-0"]}index.jsimport"babel-polyfill";functionaddAll(){returnArray.from(arguments).reduce(function(a,b){returna+b;});}运行编译babelindex.js-odist.js编译出来的dist.js"usestrict";require("babel-polyfill");functionaddAll(){returnArray.from(arguments).reduce(function(a,b){returna+b;});}并没有把Array.from转成es5语法啊？Node运行版本是8.9.3

Answer 1

什么叫转成ES5语法,这种是API,不是写法,也不是语法.babel-polyfill是用在这些API的兼容上的.直接添加在原型里了,平常该怎么用就怎么用,不用考虑兼容性.
constfn=()=>{}转成varfn=function(){}这叫转成语法.