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.
![9 Mind-Blowing WebGL Demos]()
As much as developers now loathe Flash, we're still playing a bit of catch up to natively duplicate the animation capabilities that Adobe's old technology provided us. Of course we have canvas, an awesome technology, one which I highlighted 9 mind-blowing demos. Another technology available...
![Create Namespaced Classes with MooTools]()
MooTools has always gotten a bit of grief for not inherently using and standardizing namespaced-based JavaScript classes like the Dojo Toolkit does. Many developers create their classes as globals which is generally frowned up. I mostly disagree with that stance, but each to their own. In any event...
![Using MooTools For Opacity]()
Although it's possible to achieve opacity using CSS, the hacks involved aren't pretty. If you're using the MooTools JavaScript library, opacity is as easy as using an element's "set" method. The following MooTools snippet takes every image with the "opacity" class and sets...
![Translate Content with the Google Translate API and JavaScript]()
Note: For this tutorial, I'm using version1 of the Google Translate API. A newer REST-based version is available.
In an ideal world, all websites would have a feature that allowed the user to translate a website into their native language (or even more ideally, translation would be...
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