Data Source and Methodology
The regex engine used in this tool is based on the popular open-source library, RE2 by Google, known for its speed and safety. All calculations adhere strictly to the engine's capabilities and limitations.
The Formulas Explained
Syntax: A regex pattern is enclosed within delimiters, often slashes. Example: /pattern/
Glossary of Terms
- Regular Expression: A sequence of characters defining a search pattern.
- Test String: The text against which the regex is tested.
- Match: A substring that matches the pattern defined by the regex.
Example Practical Application
To find all email addresses in a text, you could use a regex pattern like: /\b[A-Za-z0-9._%+-]+@[A-Za-z0-9.-]+\.[A-Z|a-z]{2,}\b/
Frequently Asked Questions (FAQ)
What is a regular expression?
A regular expression is a sequence of characters that define a search pattern, usually for use in pattern matching with strings.
How do I test a regular expression?
Enter your regex pattern and the test string in the fields above, then click on "Test Regex" to see the matches.
Can I use this tool for complex regex patterns?
Yes, this tool supports complex regex patterns, but ensure they are compatible with the RE2 engine's syntax and performance constraints.
What should I do if my regex doesn't work?
Check for syntax errors and ensure your regex conforms to the RE2 engine's syntax rules. Refer to the documentation for guidance.
Is this tool free to use?
Yes, our Regex Tester is completely free to use for anyone.