There seems to be no corresponding folder or file named 'react'. Maybe using npm start gives the JSX file access to 'react', I don't know where 'react' is located though.

Basically, where is 'react' located?

I looked in the node_modules folder, and there is a subfolder named react. However, there is no file named React in there.

import React from 'react';

In the above line of code, I can not figure out where React is. I tried looking in the 'react' folder that is a subfolder of node_modules

CodePudding user response：

React is exported from the React package.

import React from 'react';

In the above line, you are importing a default export. You can give it any name you want instead of React.

In the React source code you can find this default export defined in package.json.

CodePudding user response：

The word React is where you assigned whatever the 'react' library exported as default.

if you open the node_modules/react/package.json file and check it you can find following line of code,

  ...
  "main": "index.js",
  "exports": {
    ".": {
      "react-server": "./react.shared-subset.js",
      "default": "./index.js" // <----------------------------- see here
    },
    "./package.json": "./package.json",
    "./jsx-runtime": "./jsx-runtime.js",
    "./jsx-dev-runtime": "./jsx-dev-runtime.js"
  },

The package.json says the entry point is index.js so if you check the content of index.js, (exports["."]["default"] says use index.js for default import ( ie import DefaultReact from 'react' ))

'use strict';

if (process.env.NODE_ENV === 'production') {
  module.exports = require('./cjs/react.production.min.js');
} else {
  module.exports = require('./cjs/react.development.js');
}

This is not just a react specific thing, you can learn how to create custom packages from here.