Module Pattern

The module pattern uses an IIFE to create a closure that encapsulates private data and exposes a public API.

const counterModule = (function () {
  let count = 0;
  return {
    increment() {
      count++;
    },
    decrement() {
      count--;
    },
    getCount() {
      return count;
    },
  };
})();
counterModule.increment();
console.log(counterModule.getCount()); // 1