A regex is a string of text that lets you create patterns that help match, locate, and manage text.
Regex can be used any time you need to query string-based data, such as:
- Analysing command line output
- Parsing user input
- Examining server or program logs
- Handling text files with a consistent syntax, like a CSV
- Reading configuration files
- Searching and refactoring code
While doing all of these is theoretically possible without regex, when regexes hit the scene they act as a superpower for doing all of these tasks.
Errors
Type 1 Errors
-
False Positives
- Words which exist but should not be in the result
Type 2 Errors
-
False Negatives
- The words which are left out but were actually supposed to be in the result
Resources
regex101: build, test, and debug regex
The Complete Guide to Regular Expressions (Regex) - CoderPad
Regular expression syntax cheat sheet - JavaScript | MDN
Cheat Sheet
