Modern JavaScript Web Development Cookbook

Doing modules the IIFE way

Before modules became widely available, there was a fairly common pattern in use, which basically provided the same features that today's modules do. First, let's introduce a sample fragment of code, and then examine its properties:

// Source file: src/iife_counter.js/* @flow *//*    In the following code, the only thing that needs    an explicit type declaration for Flow, is "name".    Flow can work out on its own the rest of the types.*/const myCounter = ((name: string) => {    let count = 0;    const inc = () => ++count;    const get = () => count; // private    const toString = () => `${name}: ${get()}`;    return {        inc,        toString    };})("Clicks");console.log(myCounter); // an object, with methods inc and toStringmyCounter.inc(); // ...