Extract a Number from a String with JavaScript
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.
![Responsive Images: The Ultimate Guide]()
Chances are that any Web designers using our Ghostlab browser testing app, which allows seamless testing across all devices simultaneously, will have worked with responsive design in some shape or form. And as today's websites and devices become ever more varied, a plethora of responsive images...
![39 Shirts – Leaving Mozilla]()
In 2001 I had just graduated from a small town high school and headed off to a small town college. I found myself in the quaint computer lab where the substandard computers featured two browsers: Internet Explorer and Mozilla. It was this lab where I fell...
![Ana Tudor’s Favorite CodePen Demos]()
Cocoon
I love canvas, I love interactive demos and I don't think I have ever been more impressed by somebody's work than when I discovered what Tiffany Rayside has created on CodePen. So I had to start off with one of her interactive canvas pens, even though...
![Create a Twitter AJAX Button with MooTools, jQuery, or Dojo]()
There's nothing like a subtle, slick website widget that effectively uses CSS and JavaScript to enhance the user experience. Of course widgets like that take many hours to perfect, but it doesn't take long for that effort to be rewarded with above-average user retention and...
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