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 Awesome New Mozilla Technologies You’ve Never Heard Of]()
My trip to Mozilla Summit 2013 was incredible. I've spent so much time focusing on my project that I had lost sight of all of the great work Mozillians were putting out. MozSummit provided the perfect reminder of how brilliant my colleagues are and how much...
![How I Stopped WordPress Comment Spam]()
I love almost every part of being a tech blogger: learning, preaching, bantering, researching. The one part about blogging that I absolutely loathe: dealing with SPAM comments. For the past two years, my blog has registered 8,000+ SPAM comments per day. PER DAY. Bloating my database...
![MooTools 1.2 OpenLinks Plugin]()
I often incorporate tools into my customers' websites that allow them to have some control over the content on their website. When doing so, I offer some tips to my clients to help them keep their website in good shape. One of the tips...
![Creating Spacers with Flexbox]()
I was one of the biggest fans of flexbox before it hit but, due to being shuffled around at Mozilla, I never had the chance to use it in any practice project; thus, flexbox still seems like a bit of a mystery to me. This greatly...
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