Imports and Exports

We can use the keyword import to load values from other JavaScript files via relative path.

We use export to expose values for importing.

Named imports and exports

A single file can have multiple exports, and any subset of these can be imported simultaneously.

Importing from modules

3rd party libraries specify a "main" file, usually named index.js.

There's a shorter syntax for importing this file: we import the name of the module's directory (which is the name of the package in the npm registry).

E.g. assuming we had downloaded the moment library:

Similarly, importing a directory will import the index.js file in that directory.

"Legacy" imports and exports

The newer import and export syntax are usually implemented as syntax sugar on top of the older require and module.exports pattern.

The new syntax is generally better since it's statically analyzable — i.e. we can't use an expression as an import path.

There are still a variety of uses for this pattern, but in the most common use case, we should use import and export on any platform that supports them.