JS Modules

// --- mathUtils.js (The Module) ---
// Named exports
export const PI = 3.14159;

export function add(a, b) {
  return a + b;
}

// Default export (only one per file)
export default class Calculator {
  multiply(a, b) {
    return a * b;
  }
}

// --- main.js (The Consumer) ---
// Importing a default export (no braces, name it whatever)
import MyCalc from './mathUtils.js';

// Importing named exports (must use braces and exact name)
import { PI, add } from './mathUtils.js';

// You can also rename named exports on import
import { add as sum } from './mathUtils.js';

const calc = new MyCalc();
console.log(calc.multiply(2, 5)); // 10
console.log(PI); // 3.14159
console.log(sum(5, 5)); // 10