DEV Community

Regular Expressions

A regular expression (shortened as regex or regexp also referred to as regular expression) is a sequence of characters that specifies a search pattern.

Posts

👋 Sign in for the ability to sort posts by relevant, latest, or top.
Our lastmod ignored a price change: the regex that ate the first figure

Our lastmod ignored a price change: the regex that ate the first figure

Comments
3 min read
The caller's number was a timestamp: picking a phone number out of an Android call notification

The caller's number was a timestamp: picking a phone number out of an Android call notification

Comments
4 min read
A Tiny Regex Bug in Adyen's Java Library, and How My Fix Shipped in SDK v42.0.0

A Tiny Regex Bug in Adyen's Java Library, and How My Fix Shipped in SDK v42.0.0

Comments
3 min read
I tested 6 popular email regexes against 46 addresses. None passed.

I tested 6 popular email regexes against 46 addresses. None passed.

Comments
5 min read
JavaScript regex in practice: greedy vs lazy, lookarounds, and the 300 ms pattern

JavaScript regex in practice: greedy vs lazy, lookarounds, and the 300 ms pattern

Comments
3 min read
How to Learn Regex (and Stop Googling the Same Patterns)

How to Learn Regex (and Stop Googling the Same Patterns)

Comments
5 min read
Your Regex Works in JS but Fails in GA4? Full-Match, RE2, and the Patterns That Actually Work

Your Regex Works in JS but Fails in GA4? Full-Match, RE2, and the Patterns That Actually Work

Comments
2 min read
Stop Trimming \r Off Every Regex Match. .NET 11 Has AnyNewLine

Stop Trimming \r Off Every Regex Match. .NET 11 Has AnyNewLine

Comments
4 min read
Why Your Profanity Filter Blocks Scunthorpe (And How to Fix It)

Why Your Profanity Filter Blocks Scunthorpe (And How to Fix It)

Comments
5 min read
Parsing Electrical Steel Grade Codes in Python: 50A310, M310-50A and 50W310 Are the Same Steel

Parsing Electrical Steel Grade Codes in Python: 50A310, M310-50A and 50W310 Are the Same Steel

Comments
5 min read
18 of 40 Home Pages Handed Me the Same Facebook Page: facebook.com/2008

18 of 40 Home Pages Handed Me the Same Facebook Page: facebook.com/2008

Comments 1
6 min read
How to run a user's regex without letting it freeze the browser tab

How to run a user's regex without letting it freeze the browser tab

Comments
3 min read
Turning spoken commands into safe actions: regex first, the language model second

Turning spoken commands into safe actions: regex first, the language model second

Comments
4 min read
Test Your Regex in the Browser: 5 Real Bugs + a Free Online Tester

Test Your Regex in the Browser: 5 Real Bugs + a Free Online Tester

Comments
3 min read
Why Your GA4 Regex Keeps Failing — 2 Rules That Fix 99% of It

Why Your GA4 Regex Keeps Failing — 2 Rules That Fix 99% of It

1
Comments
1 min read
👋 Sign in for the ability to sort posts by relevant, latest, or top.