Introduction

When reading articles about JavaScript, you might run into the terms truthy and falsy. In this post I will explain what they are and show how to remember which values are truthy and which are falsy.

Truthy

A truthy is a value which when evaluated in the context of a Boolean evaluates to true.

Falsy

A falsy is a value which when evaluated in the context of a Boolean evaluates to false.

How to know which values are truthy and which are falsy?

There are 8 values which are falsy: 0, false, null, undefined, 0n, NaN (Not a Number), -0 and “”. Any values other than those are considered truthy values.