JavaScript Numeric Separators

By  on  

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!

Recent Features

  • By
    CSS @supports

    Feature detection via JavaScript is a client side best practice and for all the right reasons, but unfortunately that same functionality hasn't been available within CSS.  What we end up doing is repeating the same properties multiple times with each browser prefix.  Yuck.  Another thing we...

  • By
    Create a CSS Flipping Animation

    CSS animations are a lot of fun; the beauty of them is that through many simple properties, you can create anything from an elegant fade in to a WTF-Pixar-would-be-proud effect. One CSS effect somewhere in between is the CSS flip effect, whereby there's...

Incredible Demos

  • By
    prefers-color-scheme: CSS Media Query

    One device and app feature I've come to appreciate is the ability to change between light and dark modes. If you've ever done late night coding or reading, you know how amazing a dark theme can be for preventing eye strain and the headaches that result.

  • By
    CSS Transforms

    CSS has become more and more powerful over the past few years and CSS transforms are a prime example. CSS transforms allow for sophisticated, powerful transformations of HTML elements.  One or more transformations can be applied to a given element and transforms can even be animated...

Discussion

    Wrap your code in <pre class="{language}"></pre> tags, link to a GitHub gist, JSFiddle fiddle, or CodePen pen to embed!