JavaScript Recipes vs DNS Checker Pro

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.

Advanced DNS analysis with custom server support Take control of your network troubleshooting. DNS Checker Pro is the professional utility designed for system administrators and developers who need more than just a basic lookup. Verify DNS propagation instantly across reliable global resolvers (Google, Cloudflare, OpenDNS) or add your own custom DNS servers to test specific environments. Custom DNS Server Support: Need to test a private nameserver or a specific ISP? Add and manage your own list of custom DNS servers. Perfect for testing split-horizon DNS or internal networks. Multi-Server Comparison: Send queries to multiple DNS servers simultaneously. Compare results side-by-side to instantly spot propagation delays or configuration mismatches. Global Propagation Check: See how your records resolve around the world with our pre-set global server list. Comprehensive Record Analysis: Support for A, AAAA, CNAME, MX, TXT, NS, SOA and SPF records. Developer-First Design: Clean interface, dark mode support, and one-tap copy for sharing results with your team.