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 and Infinitely Scalable JS Animations]()
Back in late 2012 it was not easy to find open source projects using requestAnimationFrame() - this is the hook that allows Javascript code to synchronize with a web browser's native paint loop. Animations using this method can run at 60 fps and deliver fantastic...
![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...
![Create Spinning Rays with CSS3: Revisited]()
![Use Custom Missing Image Graphics Using MooTools]()
Missing images on your website can make you or your business look completely amateur.
Unfortunately sometimes an image gets deleted or corrupted without your knowledge.
You'd agree with me that IE's default "red x" icon looks awful, so why not use
your own missing image graphic?
The MooTools JavaScript
Note that...
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