Extract a Number from a String with JavaScript

By  on  

User input from HTML form fields is generally provided to JavaScript as a string. We've lived with that fact for decades but sometimes developers need to extract numbers from that string. There are multiple ways to get those numbers but let's rely on regular expressions to extract those numbers!

To employ a regular expression to get a number within a string, we can use \d+:

const string = "x12345david";
const [match] = string.match(/(\d+)/);
match; // 12345

Regular expressions are capable of really powerful operations within JavaScript; this practice is one of the easier operations. Converting the number using a Number() wrapper will give you the number as a Number type.

Recent Features

  • By
    Introducing MooTools Templated

    One major problem with creating UI components with the MooTools JavaScript framework is that there isn't a great way of allowing customization of template and ease of node creation. As of today, there are two ways of creating: new Element Madness The first way to create UI-driven...

  • By
    Create a Sheen Logo Effect with CSS

    I was inspired when I first saw Addy Osmani's original ShineTime blog post.  The hover sheen effect is simple but awesome.  When I started my blog redesign, I really wanted to use a sheen effect with my logo.  Using two HTML elements and...

Incredible Demos

  • By
    Create Keyboard Shortcuts with Mousetrap

    Some of the finest parts of web apps are hidden in the little things.  These "small details" can often add up to big, big gains.  One of those small gains can be found in keyboard shortcuts.  Awesome web apps like Gmail and GitHub use loads of...

  • By
    Animated AJAX Record Deletion Using Dojo

    I'm a huge fan of WordPress' method of individual article deletion. You click the delete link, the menu item animates red, and the item disappears. Here's how to achieve that functionality with Dojo JavaScript. The PHP - Content & Header The following snippet goes at the...

Discussion

  1. Dekel

    the code string.match(/(\d+)/); assumes that a match is found. If no number is present in the string, string.match(/(\d+)/) will return null, and attempting to destructure null will result in an error

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