De ultieme regex playground voor Nederlandse developers
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Step-by-step tutorials that go beyond syntax. Each guide walks through real-world patterns for parsing structured text, validating user input, and extracting data from logs, APIs, and CSV exports.
Begin Here
Build a solid foundation. This guide covers ^, $, \b, and the difference between greedy, lazy, and possessive quantifiers. Includes exercises for matching Dutch postal codes (e.g., 1071 XX) and phone numbers in +31 6 1234 5678 format.
Learn to extract structured data using numbered and named captures. Parse log lines like [2024-03-15T08:42:11Z] INFO Request handled in 234ms into timestamp, level, and message variables. Covers backreferences and non-capturing groups (?:…).
Match context without consuming characters. Use positive lookbehind <?= to find prices preceded by "EUR", and negative lookahead (?!…) to exclude reserved usernames. Practical examples with CSV field parsing and HTML attribute extraction.
A realistic email validation pattern that covers RFC 5322 essentials without going overboard. Handles jan+filter@voorbeeld.nl, subdomains like user@mailserver.example.com, and rejects common mistakes such as missing TLDs or consecutive dots.
Extract fields from comma-separated and pipe-delimited files. Handles quoted fields with embedded commas (e.g., "Amsterdam, Noord-Holland"), escaped quotes, and inconsistent whitespace. Includes a benchmark comparing regex vs. native CSV parsers.
Defensive regex for stripping HTML tags, neutralizing XSS payloads, and normalizing whitespace. Covers patterns for safe username generation, slug creation from Dutch text (handling é, ij, ï), and preventing regex denial-of-service (ReDoS) in production.
Advanced
When a full JSON parser is overkill, regex can extract key-value pairs from near-JSON responses. Covers matching nested braces with recursive-like patterns, handling escaped characters inside strings, and extracting specific fields from API error payloads.
Read GuideValidate and compare semver strings like 2.14.3-beta.1. Build patterns that enforce major.minor.patch structure, optional pre-release tags, and build metadata. Useful for dependency checking and changelog parsing.
Split Dutch and English text into meaningful tokens while preserving contractions (don't, 't), hyphenated compounds (web-applicatie), and numeric ranges (€10–25). Includes a tokenizer benchmark against NLTK and spaCy for simple use-cases.
Extract actionable insights from Apache, Nginx, and application logs. Patterns for identifying slow requests (>500ms), counting 4xx/5xx errors per endpoint, and correlating session IDs across multi-line stack traces.
Read GuideHave a regex pattern or workflow worth documenting? Submit a pull request with your guide to the RegExMakker docs repository. We accept tutorials that include runnable examples, edge-case coverage, and performance notes.
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