TypeOfNaN

Nick Scialli is a software engineer at the U.S. Digital Service.

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Learn the JavaScript Array.every() and Array.some() methods

Array.every() and Array.some() are handy JavaScript array methods that can help you test an array against specified criteria. In this post, we'll quickly learn how to use them.

What is a Higher-Order Function?

One term you might hear in the JavaScript world is "higher-order function." Today, we'll explore what it means to be a higher-order function and look at some examples in JavaScript!

The JavaScript Set Object

Set is one of my favorite built-in object types in JavaScript. Today I'll introduce the Set object and discuss some of its use cases.

What is Memoization?

One type of programming concept I really like explaining is the type that has an intimidating name but, once you learn it, is actually a pretty simple concept. This is how I feel about memoization.

What is a Thunk?

Thunk is one of those programming terms that sounds intimidating, but many of us are actually familiar with and have used them.

Set Up a Typescript React Redux Project

A basic setup for using Typescript with React and Redux.

Variable Assignment and Primitive/Object Mutability

If you're not familiar with how JavaScript variable assignment and primitive/object mutability works, you might find yourself encountering bugs that you can't quite explain.

What is a Pure Function?

Pure function is one of those terms that might be intimidating at first, but the concept is actually quite simple. In this post, I'll quickly define what pure functions are and why they're good.

Exploring the Symmetric Difference Interview Question in JavaScript

The Symmetric Difference interview question is an interesting one because it can be relatively simple to solve if you can think to use the Set object, or, seemingly very challenging or inefficient otherwise.

An Easy Way to Build a Tree in JavaScript Using Object References

Building a tree structure in JavaScript can be easy if you think in terms of references.

An Approach to JavaScript Object Schema Migration

An approach to migrating between different versions of a schema that may be foundational to your app.

Random JavaScript Tips

Sometimes I find clever, interesting, or overlooked ways to solve certain problems in JavaScript.

Debouncing with Redux Middleware

Let's implement debouncing functionality using Redux middleware!

Toggling Light/Dark Theme in React with useContext

Context was always a great option for sharing app-wide state such as theming. With the useContext hook, it became even better!

Callbacks, Promises, and Async-Await

JavaScript touts asynchronous programming as a feature. In this post, we explore callbacks, promises, and async-await to handle async programming.

Short-Circuit Evaluation in JavaScript

Short-circuit evaluation offers a clean and simple way to conditionally assign variables and handle control flow.

Writing a Custom React useDebounce Hook with Typescript

Follow along as I write a custom useDebounce React hook with Typescript.

A More Idiomatic Two-Sum Solution in JavaScript

Recently, I posted a way to solve the two-sum problem using an object to cache previous values of the array. This time, I look at a more idiomatic JavaScript approach.

Beware the Reduce / Spread Operator Combination!

It may feel fancy to use them together, but can get quite expensive.

Creating an Object Validator in JavaScript the Test-Driven Development Way

In this post, we build something useful (an object validator) using test-driven development!

An Introduction to Memoization in JavaScript

Memoization is an optimization technique used in many programming languages to reduce the number of redundant, expensive function calls.

Calculating Derived State in JavaScript Using Selectors

State management is challenging. We can make it less challenging by making sure we don’t store any redundant information in our state.

Exploring the Two-Sum Interview Question in JavaScript

The two-sum interview question is interesting to explore because it has both a brute force logical, solution, as well as a more efficient solution that can demonstrate strong CS fundamentals.

First-Class Functions in JavaScript

JavaScript has first-class functions. What does this mean and why is it important?

Why We're Looking Forward to Optional Chaining

There was recently a lot of excitement surrounding the TC39 Optional Chaining Proposal. This is why!

Object Assignment vs. Primitive Assignment in JavaScript for Beginners

A quick look at object assignment in JavaScript aimed at newcomers to the language.

Avoiding Race Conditions when Fetching Data with React Hooks

Learning how to fetch data the right way with React Hooks.

Debouncing with React Hooks

Expermenting with the relatively new React Hooks API to accomplish debounced list filtering.

The Best Whiteboard Interview Advice I Ever Received

In this article, I intend to pass along the best advice I ever received for going through a whiteboard interview.

A 100DaysOfCode Front-End Curriculum

This is a somewhat opinionated curriculum for learning front-end development during 100DaysOfCode.

Fun with React and Git Hooks

One topic I have gotten more and more excited about throughout my software development career is quality!