for...in vs. for...of in JavaScript
Compare for...in and for...of in JavaScript, including keys, values, arrays, objects, iterables, inherited properties, and choosing the clearest loop.
Articles
Development, page 25 of 27
Development is the broadest category in my writing, so it works as the main archive rather than a narrow subject label. It brings together implementation notes and technical decisions, with delivery lessons from across the rest of the site.
For...in vs. for...of in JavaScript. 
JSON.parse() and JSON.stringify() Explained for Beginners. JSON.parse()andJSON.stringify()Explained for BeginnersJSON.parse()andJSON.stringify()explained clearly, including when to convert data, common mistakes, localStorage use, and why functions disappear.
Live and Static DOM Collections in JavaScript. Live and Static DOM Collections in JavaScript
Understand live HTMLCollection views, static NodeList snapshots, mutation‑skipping bugs, Array.from() conversion, and safe DOM iteration in 2016.
Array.from() and Array.of() in JavaScript. Array.from()andArray.of()in JavaScriptArray.from()andArray.of()in JavaScript explained with NodeLists, array‑like objects, generated arrays, and whynew Array()can still catch people out.
The arguments Object vs. Rest Parameters in JavaScript. The
argumentsObject vs. Rest Parameters in JavaScriptThe
argumentsobject vs. rest parameters in JavaScript, including readability, array behaviour, arrow function differences, and modern best practices.
Why input.value Returns a String in JavaScript. Why
input.valueReturns a String in JavaScriptUnderstand why
input.valuereturns a string, howvalueAsNumberandcheckeddiffer, and how to handle strings, files and missingFormDataentries.
Object Property Shorthand and Computed Property Names in JavaScript. Object Property Shorthand and Computed Property Names in JavaScript
Use object property shorthand and computed property names in JavaScript for cleaner literals, derived keys, method shorthand, and overwrite cautions.
Client‑Side Form Validation with the HTML Constraint Validation API. Client‑Side Form Validation with the HTML Constraint Validation API
Use HTML constraint validation attributes and APIs to improve client‑side form feedback without replacing accessible errors or server‑side checks.
Object.assign() in JavaScript: Merging and Shallow Copies. Object.assign()in JavaScript: Merging and Shallow CopiesUse Object.assign() in JavaScript for merging and shallow copies, with target mutation, overwrite rules, nested‑object cautions, and newer alternatives.
Using Feature Detection in Front‑End Development. Using Feature Detection in Front‑End Development
Use feature detection in front‑end work by checking browser capability, choosing enhancement or fallback paths, and avoiding fragile user‑agent assumptions.
Rendering Lists in React and Why Keys Matter. Rendering Lists in React and Why Keys Matter
Render lists in React with stable keys, avoiding index and random‑key bugs, preserving component state correctly through filtering, sorting, and reordering.
Writing Safer JavaScript for Older Browsers. Writing Safer JavaScript for Older Browsers
Write safer JavaScript for older browsers by checking support, avoiding fragile assumptions, containing failures, and keeping core interactions usable.
Understanding call, apply, and bind in JavaScript. Understanding
call,apply, andbindin JavaScriptUnderstand call, apply, and bind in JavaScript, including this context, borrowed methods, callbacks, partial application, and production review caveats.
How Inheritance Works in the JavaScript Prototype Chain. How Inheritance Works in the JavaScript Prototype Chain
The JavaScript prototype chain underpins inheritance, enabling object property sharing. Here, I explore its workings, property searching, and quirks.
JavaScript Build Tools and Module Formats. JavaScript Build Tools and Module Formats
A practical overview of JavaScript build tools and module formats, covering globals, CommonJS, AMD, Browserify, bundling, and project trade‑offs.
Type Coercion in JavaScript: Implicit vs. Explicit Conversion. Type Coercion in JavaScript: Implicit vs. Explicit Conversion
Type coercion in JavaScript explained clearly, including implicit vs. explicit conversion, equality surprises, string concatenation, and number casting.
Five Tips for Transitioning from Permanent to Freelancing. Five Tips for Transitioning from Permanent to Freelancing
Thinking of moving from permanent employment to freelancing? Follow these 5 tips for a smooth transition and establish yourself as a successful freelancer.
Object URLs Need a Lifecycle: Creating and Revoking Blob URLs. Object URLs Need a Lifecycle: Creating and Revoking Blob URLs
Create object URLs for local file previews, revoke them at the right time, and avoid retaining Blob data too long or breaking a browser consumer.