Exporting data from a JavaScript module

26 Sep 2023

ModuleExports

Using the `export` keyword

The most common method for exporting data from a JavaScript module is by using the export keyword. You can use it with variables, functions, or objects. Let’s explore some examples:

Exporting a Variable

To export a variable, you can simply use the export keyword before the declaration:

export const myVariable = "Hello, world!";

This exports the variable myVariable with the value "Hello, world!".

Exporting a Function

To export a function, you can also use the export keyword before the function declaration:

export function myFunction() {
  return "Hello, world!";
}

This exports the function myFunction which returns the string "Hello, world!".

Exporting an Object

To export an object, you can assign it to a variable and export that variable:

const myObject = {
  name: "John",
  age: 28
};

export { myObject };

This exports the object myObject with its properties name and age.

Using the `default` keyword

In addition to the export keyword, JavaScript also provides the default keyword to export a default value from a module. This is useful when you want to export a single value or when you want to have a fallback export.

Exporting a Default Value

To export a default value, you can use the export default syntax:

const myVariable = "Hello, world!";

export default myVariable;

This exports the value of myVariable as the default export of the module.

You can also combine the export statement with the declaration itself, like this:

export default function() {
  return "Hello, world!";
}

This exports an anonymous function as the default export.

Importing the Exported Data

To use the exported data in another module, you need to import it. You can do this using the import statement. Let’s see some examples:

Importing a Single Export

To import a single exported value, you can use the import statement followed by the name of the export:

import { myVariable } from './myModule.js';

console.log(myVariable); // Output: Hello, world!

Importing a Default Export

To import the default export, you can use the import statement without the curly braces:

import myVariable from './myModule.js';

console.log(myVariable); // Output: Hello, world!

Importing Multiple Exports

You can also import multiple exports by listing them inside the curly braces:

import { myVariable, myFunction } from './myModule.js';

console.log(myVariable); // Output: Hello, world!
console.log(myFunction()); // Output: Hello, world!

Conclusion

Exporting data from a JavaScript module is essential for creating modular and reusable code. By using the export and default keywords, you can easily expose variables, functions, and objects to be used in other parts of your application. Don’t forget to import the exported data properly in order to utilize it effectively. Now you have the knowledge and tools to export data from JavaScript modules with ease! #JavaScript #ModuleExports

Using the export keyword