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.
![5 More HTML5 APIs You Didn’t Know Existed]()
The HTML5 revolution has provided us some awesome JavaScript and HTML APIs. Some are APIs we knew we've needed for years, others are cutting edge mobile and desktop helpers. Regardless of API strength or purpose, anything to help us better do our job is a...
![Creating Scrolling Parallax Effects with CSS]()
Introduction
For quite a long time now websites with the so called "parallax" effect have been really popular.
In case you have not heard of this effect, it basically includes different layers of images that are moving in different directions or with different speed. This leads to a...
![Facebook Open Graph META Tags]()
It's no secret that Facebook has become a major traffic driver for all types of websites. Nowadays even large corporations steer consumers toward their Facebook pages instead of the corporate websites directly. And of course there are Facebook "Like" and "Recommend" widgets on every website. One...
![Instagram For MooTools]()
If you're still rocking an iPhone and fancy taking a photo every now and then, you'd be crazy not to be using an app called Instagram. With Instagram you take the photos just as you would with your native iPhone camera app, but Instagram...
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