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.
![Create Spinning Rays with CSS3: Revisited]()
![Create a CSS Cube]()
CSS cubes really showcase what CSS has become over the years, evolving from simple color and dimension directives to a language capable of creating deep, creative visuals. Add animation and you've got something really neat. Unfortunately each CSS cube tutorial I've read is a bit...
![Fullscreen API]()
As we move toward more true web applications, our JavaScript APIs are doing their best to keep up. One very simple but useful new JavaScript API is the Fullscreen API. The Fullscreen API provides a programmatic way to request fullscreen display from the user, and exit...
![CSS Fixed Position Background Image]()
Backgrounds have become an integral part of creating a web 2.0-esque website since gradients have become all the rage. If you think gradient backgrounds are too cliche, maybe a fixed position background would work for you? It does provide a neat inherent effect by...
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