Tag: JavaScript

1. Object.hasOwn vs. hasOwnProperty: Safe Property Checks Without Pitfalls

   Apr 2, 2025

   obj.hasOwnProperty(key) looks harmless, but it breaks with null prototype objects and with overridden prototype methods. Object.hasOwn(obj, key) is the static, robust alternative that avoids exactly these pitfalls and should be the default choice for property checks in modern code.

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2. Array.fromAsync in Practice: Turning Async Iterables into Arrays Cleanly

   Mar 31, 2025

   Anyone who has turned an asynchronous data stream into an array with manual loops and push calls knows the race conditions and the awkward error handling that come with it. Array.fromAsync solves exactly this problem: a single built in method that collects async iterables, generators and mixed promise lists in the correct order into an array.

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3. JavaScript Nullish Coalescing and Optional Chaining Explained

   Mar 29, 2025

   Nullish Coalescing (??) and Optional Chaining (?.) are the most important additions to JavaScript since ES2020. They replace fragile && chains and || fallbacks with precise, readable operators, with the crucial difference that they react only to null and undefined, not to every falsy value.

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4. Web Share API: Native Share Dialog in JavaScript

   Mar 18, 2025

   Custom share buttons hardcoded to a handful of social media platforms are outdated. The Web Share API opens the operating system's native share dialog, and the user decides which app to use: WhatsApp, Telegram, Email, Notes, or anything else. The result is better UX with less code and no dependency on third-party SDKs.

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5. JavaScript Pattern Matching Proposal: the match Expression and Structural Matching

   Mar 16, 2025

   switch/case only handles primitive equality, nested conditions quickly become unreadable, and there is no expression character at all. The TC39 Pattern Matching Proposal changes that: a match expression checks structure, type, shape, and value of an object at the same time, declaratively, exhaustively, and without a fallthrough bug.

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6. WeakMap and WeakSet: Private Object State Without Memory Leaks

   Mar 16, 2025

   An ordinary Map used to associate objects with private state prevents those objects from ever being collected by the garbage collector as long as the map exists. WeakMap and WeakSet solve exactly this problem by only weakly referencing their keys, enabling private state that automatically disappears along with its associated object.

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7. Web Workers in JavaScript: Mastering Multithreading in the Browser

   Mar 14, 2025

   JavaScript is single-threaded, but that is not a law of nature for browser applications. Web Workers bring real multithreading to the browser: CPU-intensive calculations, file processing, encryption and AI inference run in background threads while the UI thread stays responsive and processes user interactions smoothly.

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8. Module Federation and Micro-Frontends in JavaScript

   Mar 12, 2025

   Module Federation in Webpack 5 solves what has long been the hardest problem in micro-frontend architectures: how multiple independent teams can combine their JavaScript bundles at runtime, without loading shared dependencies multiple times or sharing a central build pipeline.

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9. JavaScript using: Explicit Resource Management with using and await using

   Mar 4, 2025

   The new using keyword in JavaScript automates releasing resources when a scope is left: database connections, file handles, locks and workers are guaranteed to be cleaned up, whether the block ends normally, throws an exception, or triggers an early return.

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10. JavaScript Error Cause: Structured Error Handling with error.cause

    Feb 28, 2025

    In JavaScript, the original error gets lost on re-throw: an Error is replaced by another one, and the context disappears. The error.cause feature from ES2022 solves exactly this problem. It allows structured error chains where each layer keeps its own context while the root error is passed through.

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