using babel

babel

Assumme that we have already installed babel-cli command using `npm install --global babel-cli`.

1. Configuration .babelrc, the basic format of this file is shown as the following:

{
  "presets": [],
  "plugins": []
}

2. Install some plunins
   For plugins allow Babel to parse specific types of syntax, So we need to install particular plunin if we need 
   to transform specific source code.

3. Using babel to convert src files
   For example, we can use `babel "src" -d "dist"` to convert files, where the src is a directory in which source js 
   files are stored and the dist is the directory into which we want to ouput the transformed files.

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The transpiling can be done in the following three ways:

1. Via .babelrc (Recommended)
   Bable will resolve the .babelrc configuration file to do some specific transpiling work.
2. Via CLI
   For example,
     babel --plugins some-plugin source.js
3. Via Node API
   For exapmple,
     require("babel-core").transform("code", {
        plugins: ["some-plugin"]
     });