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.
![CSS Animations Between Media Queries]()
CSS animations are right up there with sliced bread. CSS animations are efficient because they can be hardware accelerated, they require no JavaScript overhead, and they are composed of very little CSS code. Quite often we add CSS transforms to elements via CSS during...
![An Interview with Eric Meyer]()
Your early CSS books were instrumental in pushing my love for front end technologies. What was it about CSS that you fell in love with and drove you to write about it?
At first blush, it was the simplicity of it as compared to the table-and-spacer...
![MooTools Gone Wild: Element Flashing]()
If you're like me and lay awake in bed at night, you've flipped on the TV and seen the commercials: misguided, attention-starved college girls fueled by alcohol ruining their futures by flashing lame camera-men on Spring Break. Why do they do it? Attention...
![MooTools Flashlight Effect]()
Another reason that I love Twitter so much is that I'm able to check out what fellow developers think is interesting. Chris Coyier posted about a flashlight effect he found built with jQuery. While I agree with Chris that it's a little corny, it...
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