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Chainable Methods: Write Your Own Lodash
Build a tiny, fast, chainable utility library from scratch — complete with lazy evaluation, mixins, and TypeScript types. Introduction Fluent, chainable APIs are addictive: _(users).map(‘name’).filter(Boolean).sortBy().take(5).value(); They read like English, encourage small reusable steps, and keep state local to the chain. Lodash popularized the style with _.chain() and later implicit chaining via _(). But you don’t need a…
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Memoization Patterns in Vanilla JS
Speeding up expensive function calls with caching strategies you can write by hand Introduction Every developer has faced this: a function runs fine the first time, but when called repeatedly — especially with the same inputs — it becomes a performance bottleneck. That’s where memoization comes in. Memoization is a fancy word for a simple idea: cache the results of…
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IIFE: The Pattern You Should Know
Why Immediately Invoked Function Expressions still matter in modern JavaScript. Introduction Before ES6 modules, IIFEs (Immediately Invoked Function Expressions) were everywhere. They powered jQuery plugins, AngularJS, and even big frameworks like React in its early days. Today, with import/export and let/const, many devs think IIFEs are dead. But here’s the truth: IIFEs are still a…
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Partial Application vs. Currying: Know the Difference
Two cousins in functional programming that look similar, but serve different purposes. Introduction If you’ve been around JavaScript long enough, you’ve seen both partial application and currying tossed around in blogs, libraries (like Lodash, Ramda), and interviews. Developers often confuse them because both involve breaking down arguments and reusing functions. But here’s the deal: partial…
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bind, call, and apply Made Simple
How to control this in JavaScript without losing your mind. Introduction Few things confuse JavaScript developers more than this. It behaves differently depending on how a function is called. To make matters worse, we also have three helpers—bind, call, and apply—that let us manually control this. Good news: these aren’t magic. Once you see the patterns,…
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Function Currying: Fun & Practical
How to break functions into bite-sized calls for flexibility, reuse, and clarity in JavaScript. Introduction At first glance, function currying feels like one of those “fancy functional programming ideas” that you’ll never actually use in day-to-day development. But once you understand it, you’ll see it everywhere — from event handlers to config builders to React hooks. Currying…
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How to Use Object.create() Like a Pro
Practical patterns, gotchas, and copy-paste snippets to leverage prototypes without classes or constructors. Introduction Most of us learn JavaScript inheritance through ES6 classes or old-school constructor functions. Under the hood, though, it’s all the prototype chain — and the cleanest doorway into that world is Object.create(). Object.create() lets you build objects that delegate to another object (their…
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ES6 Classes vs. Prototypes: Who Wins?
Understanding the two faces of inheritance in JavaScript — syntax sugar vs raw mechanics, and which one you should use today. Introduction If you’ve been coding in JavaScript for a while, you’ve probably seen both styles: // Prototype-basedfunction Animal(name) { this.name = name;}Animal.prototype.speak = function() { console.log(this.name + ” makes a sound.”);};// ES6 Classclass Dog extends Animal {…
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Prototype Chain: The Core of JavaScript Inheritance
A deep dive into how objects link together in JavaScript, how __proto__ and prototype really work, and why understanding the prototype chain saves you from bugs and design mistakes. Introduction JavaScript doesn’t have “classes” in the same sense as Java or C++. Under the hood, it’s all about objects linked to other objects. This linking…
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The Role of Immutability in Better Code
Why treating data as read-only leads to fewer bugs, faster UIs, cleaner tests, and simpler mental models — with practical JavaScript patterns you can copy-paste. Introduction Ask five developers what “immutability” means and you’ll get seven answers. Some say it’s a functional-programming thing. Others think it’s just for Redux. The truth: immutability is a design choice that…