Regex Cheat Sheet for Developers

Basic Syntax

| Pattern | Meaning | |---------|---------| | . | Any character except newline | | \d | Digit (0-9) | | \w | Word character (a-z, A-Z, 0-9, _) | | \s | Whitespace | | ^ | Start of string | | $ | End of string |

Quantifiers

| Pattern | Meaning | |---------|---------| | * | 0 or more | | + | 1 or more | | ? | 0 or 1 | | {3} | Exactly 3 | | {3,5} | Between 3 and 5 |

Common Patterns

Email Validation

^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}$

URL

https?:\/\/(www\.)?[-a-zA-Z0-9@:%._\+~#=]{1,256}\.[a-zA-Z0-9()]{1,6}\b([-a-zA-Z0-9()@:%_\+.~#?&//=]*)

Phone Number (US)

^(\+1)?[-.\s]?\(?[0-9]{3}\)?[-.\s]?[0-9]{3}[-.\s]?[0-9]{4}$

Strong Password

At least 8 chars, 1 uppercase, 1 lowercase, 1 number, 1 special:

^(?=.*[a-z])(?=.*[A-Z])(?=.*\d)(?=.*[@$!%*?&])[A-Za-z\d@$!%*?&]{8,}$

IPv4 Address

^(?:(?:25[0-5]|2[0-4]\d|[01]?\d\d?)\.){3}(?:25[0-5]|2[0-4]\d|[01]?\d\d?)$

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