JavaScript Recipes

An everyday JavaScript reference, from strings and collections to async work and design patterns. Every example comes with an explanation, and most of them run.

• 23 sections: basic types, arrays and collections, classes, files, serialization, functions and arrow expressions, exceptions, regular expressions, async operations, databases, algorithms, design patterns.
• Run in the app: the example actually runs and the output appears under the code. Needs an internet connection.
• What changed in new versions: 10 sections from ES2015 to ES2024, with the old and the new code side by side.
• Keyword and function reference: over 170 articles, open in full, with no daily limit.
• SQL alongside: over 200 queries against a live practice database (JOIN, GROUP BY, subqueries, data types).
• Edit examples and add your own; they stay in the app and are always at hand.
• Search looks inside the code itself, not just the titles: remember a fragment and you will find the example.
• Everything except running works offline. No account needed.

WHAT THE FREE VERSION INCLUDES
12 runs and 12 edits a day; the counter resets every morning. The keyword reference is open without limits. Up to 5 examples of your own.

The full version unlocks every example, lifts the daily limits and raises the run limit to 30 a day. One purchase, no subscription.

Built by a developer for developers. In active development since 2015.