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.
![Convert XML to JSON with JavaScript]()
If you follow me on Twitter, you know that I've been working on a super top secret mobile application using Appcelerator Titanium. The experience has been great: using JavaScript to create easy to write, easy to test, native mobile apps has been fun. My...
![Designing for Simplicity]()
Before we get started, it's worth me spending a brief moment introducing myself to you. My name is Mark (or @integralist if Twitter happens to be your communication tool of choice) and I currently work for BBC News in London England as a principal engineer/tech...
![WebKit Marquee CSS: Bringin’ Sexy Back]()
We all joke about the days of Web yesteryear. You remember them: stupid animated GIFs (flames and "coming soon" images, most notably), lame counters, guestbooks, applets, etc. Another "feature" we thought we had gotten rid of was the marquee. The marquee was a rudimentary, javascript-like...
![Duplicate the jQuery Homepage Tooltips Using MooTools]()
The jQuery homepage has a pretty suave tooltip-like effect as seen below:
Here's how to accomplish this same effect using MooTools.
The XHTML
The above XHTML was taken directly from the jQuery homepage -- no changes.
The CSS
The above CSS has been slightly modified to match the CSS rules already...
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