Regular Expressions 101: A Beginner's Guide

What is Regex?

Regular expressions (regex) are patterns used to match character combinations in strings. They're the Swiss Army knife of text processing.

Essential Building Blocks

• . (dot) — Matches any single character.
• * — Matches zero or more of the preceding element.
• + — Matches one or more of the preceding element.
• ? — Makes the preceding element optional.
• ^ — Matches the start of a string.
• $ — Matches the end of a string.
• [abc] — Matches any character in the brackets.
• \d — Matches any digit (0-9).
• \w — Matches any word character (a-z, A-Z, 0-9, _).

Practical Examples

Email: ^[\w.-]+@[\w.-]+\.\w{2,}$

Phone: ^\+?[1-9]\d{1,14}$

URL: ^https?://[\w.-]+\.[a-z]{2,}

Test Your Patterns

Don't guess—test! Use our Regex Tester to validate your patterns with real-time highlighting.