Modules
JavaScript modules allow you to break up your code into separate files.
This makes it easier to maintain the code-base.
ES Modules rely on the import and export statements.
1. Export
You can export a function or variable from any file.
Let us create a file named person.js, and fill it with the things we want to export.
There are two types of exports: Named and Default.
You can create named exports two ways. In-line individually, or all at once at the bottom.
Example :-
a. In-line individually :-
person.js
export const name = "Jesse"
export const age = 40
b. All at once at the bottom :-
person.js
const name = "Jesse"
const age = 40
export { name, age }
b. Default Exports
Let us create another file, named message.js, and use it for demonstrating default export.
You can only have one default export in a file.
Example :-
message.js
const name = "Jesse";
const age = 40;
return name + ' is ' + age + 'years old.';
};
export default message;
2. Import
You can import modules into a file in two ways, based on if they are named exports or default exports.
Named exports must be destructured using curly braces. Default exports do not.
Example :-
Import named exports from the file person.js:
import { name, age } from "./person.js";
Example :-
Import a default export from the file message.js:
import message from "./message.js";