Intercepting function or method invocation in JavaScript. Monkey-patching or proxies. Let’s talk about that. — The other day I had an object and needed to know when any of its methods were invoked. There were many methods on that object, and these methods were invoked throughout a lot of files. So it seemed impractical to add an extra line of code after every invocation to…

Have a look at how you can add extra styles to a React component with styled-components or @emotion/css. — As a React Front-End developer, you sometimes need to take an existing React component and apply extra styles to it. It could be because you want to extend a 3rd party library component or simply because you want to make more variants of some component in your application. Let’s see…

What is a Monad? You don’t have to be a category theory expert to understand. You have to know JavaScript Promises. — Like every other programmer, I wanted to know, what Monads are. But every time you search for Monads on the internet, you get flooded with category theory papers. And other resources don’t seem to make much sense either. To learn what Monads are, I did it the hard way. I…

Let’s Get a Grasp of Composition Equivalences in Haskell. — I’m a JavaScript developer by day and a Haskell fan by night. And just recently, I stumbled upon (.) . (.) in a Haskell. At first, I had no idea whatsoever what this is. If you’re facing the same problem, you’ve come to the right place. Let’s see what it…

All you need is recursion — a small demonstration of how versatile concept recursion is. — To understand recursion, one must first understand recursion. — Stephen Hawking I couldn’t but notice that a lot of programmers have difficulty understanding recursion. Most of the time, it’s not that they don’t know how to write a recursive function, but more so about how to actually think recursively. I…

What are JavaScript generators? In-depth tutorial and real use case examples. — In the previous article, we looked at JavaScript Iterables and Iterators. They’re prerequisites to Generators and will give you a better understanding of today’s topic. If you don’t know what Iterables and Iterators are, read it now and come back here. First, we’ll go through some theory and towards the…

Lazy evaluation, every functional programmer’s wet dream. Soon enough, we will look at generators. But first, let's get a grasp of what… — Lazy evaluation, every functional programmer’s wet dream. Soon enough, we will look at generators. But first, let's get a grasp of what iterators and iterables are because to me, they’re a prerequisite for generators. Lazy evaluation Lazy evaluation means to delay the evaluation of an expression until it’s needed. Lazy evaluation is…

Which JavaScript array flattening method is the fastest and the slowest? Let’s find out. — What is array flattening? Array flattening is process of converting multi-dimensional array to single-dimensional array. Single-dimensional array: const arr = [1, 2, 3] Multi-dimensional array: const arr_2 = [1, [2, [3]]] When you flatten arr_2 you get: const arr_2_flattened = [1, 2, 3]; Performance testing

Are you trying to find out how do you handle a mouse up event outside an element that you originally pressed? Let’s dig in and see the… — I’ve been working on a personal “Smart Home” / “IoT” project recently and came across a problem that I believe a lot of other people could be facing as well. In different shape or form. I’ve got a frontend application that remotely controls a water pump. That water pump is…