JavaScript Truthy and Falsy: A Deep Dive

Grasp JavaScript's type coercion with practical examples and avoid common pitfalls

Working with JavaScript’s truthy and falsy values used to trip me up. Sure, I knew the basics - false is falsy, true is truthy. But the edge cases? Those were tricky. Let’s dive into what I’ve learned about this fundamental yet often misunderstood concept.

The Eight Falsy Values

In JavaScript, there are exactly eight falsy values. Everything else is truthy. Here they are:

false       // The boolean false
0           // The number zero
-0          // Negative zero
0n          // BigInt zero
""          // Empty string
null        // Absence of any value
undefined   // Uninitialized value
NaN         // Not a Number

The Edge Cases That Break Your Brain

Type coercion in JavaScript creates some truly mind-bending scenarios.