export default is used to export a single class, function or primitive from a script file.
The export can also be written as
export default function SafeString(string) {
this.string = string;
}
SafeString.prototype.toString = function() {
return "" + this.string;
};
This is used to import this function in another script file
Say in app.js, you can
import SafeString from './handlebars/safe-string';
As the name says, it's used to export functions, objects, classes or expressions from script files or modules
Utiliites.js
export function cube(x) {
return x * x * x;
}
export const foo = Math.PI + Math.SQRT2;
This can be imported and used as
App.js
import { cube, foo } from 'Utilities';
console.log(cube(3)); // 27
console.log(foo); // 4.555806215962888
Or
import * as utilities from 'Utilities';
console.log(utilities.cube(3)); // 27
console.log(utilities.foo); // 4.555806215962888
When export default is used, this is much simpler. Script files just exports one thing. cube.js
export default function cube(x) {
return x * x * x;
};
and used as App.js
import Cube from 'cube';
console.log(Cube(3)); // 27