JavaScript Numeric Separators

Writing good code is important — writing code that’s easily human readable is a next level skill. It’s not often that APIs are introduced whose seemingly only useful function is making code more readable, but let me introduce you to JavaScript numeric separators: an API that lets developers use underscores to make numbers more readable!

Consider the following number in your code:

// No commas for numbers in JavaScript
const oneHundredThousand = 100000;

Large numbers have always been difficult to mentally parse for engineers, so using underscores to make code more readable is a total win:

const oneMillion = 1_000_000; // 1000000
const decimals = 1_000_00.01_02_03 // 100000.010203

The only real rule with numeric separators is that the number cannot start or end with an underscore.

Numeric separators within JavaScript seem like spec creators gifting developers a feature. As an engineer, I’ll take all I can get. You never stop learning in the world of JavaScript!