To define a default export in a module, you can simply use the export default syntax followed by the value or functionality you want to export. Here’s an example:

// math.js
const add = (a, b) => a + b;
const subtract = (a, b) => a - b;

export default {
  add,
  subtract,
};

In the above code, we are exporting an object with two functions, add and subtract, as the default export. This syntax allows us to import both functions together in another module by simply assigning them to a variable during the import.

// main.js
import mathFunctions from './math.js';

const result = mathFunctions.add(5, 3); // 8

In the main.js module, we import the default export from math.js and assign it to the mathFunctions variable. We can then access the add function directly from the mathFunctions object.

Alternatively, you can also import the default export and rename it to a different variable name during the import, like this:

import { add as sum } from './math.js';

const result = sum(5, 3); // 8

In this example, we are importing the default export add from math.js and renaming it to sum during the import. This allows us to use sum instead of add in our code.

Default exports can be very useful when you have a module that primarily exports a single value or functionality. They provide a clean and straightforward way to interact with and use those exports in your JavaScript applications.

#javascript #modules