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
    JavaScript Promise API

    While synchronous code is easier to follow and debug, async is generally better for performance and flexibility. Why "hold up the show" when you can trigger numerous requests at once and then handle them when each is ready?  Promises are becoming a big part of the JavaScript world...

  • By
    Being a Dev Dad

    I get asked loads of questions every day but I'm always surprised that they're rarely questions about code or even tech -- many of the questions I get are more about non-dev stuff like what my office is like, what software I use, and oftentimes...

Incredible Demos

  • By
    CSS Ellipsis Beginning of String

    I was incredibly happy when CSS text-overflow: ellipsis (married with fixed width and overflow: hidden was introduced to the CSS spec and browsers; the feature allowed us to stop trying to marry JavaScript width calculation with string width calculation and truncation.  CSS ellipsis was also very friendly to...

  • By
    JavaScript Copy to Clipboard with Branding

    I published a post a year ago detailing how you can copy to the clipboard using JavaScript.  The post was very popular and why would it be?  Copying content from a webpage without needing to use the default browser functions is awesome.  One trend I've...

Discussion

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