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 3D Folding Animation]()
Google Plus provides loads of inspiration for front-end developers, especially when it comes to the CSS and JavaScript wonders they create. Last year I duplicated their incredible PhotoStack effect with both MooTools and pure CSS; this time I'm going to duplicate...
![How to Create a Twitter Card]()
One of my favorite social APIs was the Open Graph API adopted by Facebook. Adding just a few META tags to each page allowed links to my article to be styled and presented the way I wanted them to, giving me a bit of control...
![RealTime Stock Quotes with MooTools Request.Stocks and YQL]()
It goes without saying but MooTools' inheritance pattern allows for creation of small, simple classes that possess immense power. One example of that power is a class that inherits from Request, Request.JSON, and Request.JSONP: Request.Stocks. Created by Enrique Erne, this great MooTools class acts as...
![Facebook-Style Modal Box Using MooTools]()
In my oh-so-humble opinion, Facebook's Modal box is the best modal box around. It's lightweight, subtle, and very stylish. I've taken Facebook's imagery and CSS and combined it with MooTools' awesome functionality to duplicate the effect.
The Imagery
Facebook uses a funky sprite for their modal...
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