This article walks through a step‑by‑step implementation of JavaScript's Promise, covering prototype methods, static helpers like resolve, reject, all, and race, with detailed code examples, execution flow explanations, and a summary of the underlying observer pattern.
This article introduces Deno 1.0.0, outlines its security‑focused design and TypeScript support, provides step‑by‑step installation commands for macOS, Linux, and Windows, demonstrates a simple Hello World server, and explains required permissions and how it compares to Node.js.
This article explains how Node.js’s AsyncHooks API can be used to implicitly propagate request context across asynchronous calls, illustrates the mechanism with login flow diagrams, compares explicit context handling in frameworks like Express and Egg, and discusses performance and adoption considerations.
This article explains how Alibaba Cloud’s ConsoleOS implements a JavaScript and CSS sandbox for micro‑frontend applications, covering the underlying principles, code examples, native object simulation via iframes, CSS isolation techniques, and integration tips for other micro‑frontend frameworks.
This article examines TypeScript—a Microsoft‑backed JavaScript superset—detailing its static‑typing benefits, improved readability, bug reduction, and active ecosystem while also discussing learning costs, slower development speed, library compatibility issues, and the necessity of compilation, helping developers decide whether to adopt it.
This article introduces Nightwatch.js 1.3, outlines its new BDD interface, additional assertions and APIs, provides step‑by‑step installation of Nightwatch and browser drivers via npm, explains CLI options, demonstrates running a sample test, and offers guidance on unit testing and example projects.
Deno 1.0, the Rust‑written JavaScript/TypeScript runtime created by Ryan Dahl, introduces a CLI, a Rust‑based core, a new plugin system, and an HTTP server that handles about 25k requests per second with low latency, positioning it as a modern alternative to Node.js.
The article reflects on how frontend development has evolved from battling performance, compatibility, and legacy issues to exploring its true potential without constraints, discusses current bottlenecks in frameworks, tooling, and languages, and looks ahead to emerging technologies such as ESBuild, Deno, and Figma that may shape its future.
This article compiles over 70 Baidu open‑source projects spanning front‑end libraries, back‑end platforms, mobile frameworks, AI tools, and infrastructure components, providing concise descriptions of each to help developers discover useful resources across a wide range of technologies.
This weekly tech roundup explains the continuation concept in JavaScript, shows how CallCC underpins React hooks, highlights 2020 front‑end trends like low‑code, serverless and AI‑driven UI generation, and reports on recent Flutter web developments and a controversial COVID‑related news story.
The article explains JavaScript’s single‑threaded nature and how asynchronous programming—using callbacks, timers, Ajax, and Promises—relies on the event loop to manage macro‑tasks and micro‑tasks, illustrates execution order, warns against callback hell, and provides a custom Promise implementation.
This article introduces Boa, a Node.js library that bridges CPython, enabling JavaScript developers to import and use Python packages—especially machine‑learning libraries like PyTorch—seamlessly within Node.js, complete with practical code examples and API explanations.
This article chronicles Vue's journey from its first 0.6.0 release through major milestones like 1.0, 2.0, and the upcoming 3.0, explains the architectural changes, reactive system overhaul, Composition API, and provides practical code examples for migration and local experimentation.
This article explains the technical principles and step‑by‑step implementation of QR code login used by major platforms like WeChat and Taobao, covering server‑side UUID generation, Redis storage, token exchange, client polling, JSONP handling, and concrete code examples.
This article walks through the complete implementation of a match‑3 (three‑in‑a‑row) game using Vue, covering the core grid logic, swap mechanics, combo detection, crushing, sorting, filling new tiles, move‑possibility checks, and the Vue rendering pipeline with animation states.
This article details the design and implementation of a JavaScript library that enables TV remote navigation for webview‑based H5 pages, covering screen adaptation, focus management, scrolling logic, event handling, and practical usage within a TV‑side hardware product.
The article describes how Youzan Retail built a unified, cross‑platform printing library—using JavaScript as a common runtime—to replace duplicated native implementations, evolve its template language from JSON to HTML, and translate rendered receipts into ESC/POS commands, supporting iOS, Android, Java, PC and future Node.js services.
This article walks through the step‑by‑step creation of a JavaScript Promise implementation, explains why true chaining requires returning a new Promise from then, demonstrates mock asynchronous calls, and provides detailed code examples and execution logs to illustrate the complete chain behavior.
This article introduces the G2 JavaScript visualization engine, highlights its ease of creating interactive, data‑driven charts, and provides three complete code examples—including an app user distribution chart, an enterprise cash‑flow chart, and a dynamic bar chart—demonstrating how to render Canvas or SVG graphics with minimal effort.
Despite the rise of modern frameworks like React, Vue, and Angular, 97.5% of sites still use jQuery, and the newest jQuery release focuses on essential security patches while offering a slimmer build that removes ajax, highlighting the library’s continued stability and relevance for front‑end developers.
This article provides a thorough, step‑by‑step explanation of the entire browser request‑response cycle—including URL parsing, DNS lookup, TCP connection, server handling, response processing, and the detailed rendering pipeline—offering clear insight for developers and interview preparation.
jQuery 3.5.0 focuses on security fixes, removes a vulnerable regex from htmlPrefilter, offers a migration plugin to restore the old behavior, and introduces .even() and .odd() methods as replacements for the deprecated positional selectors.
This article explains how Vue 2 implements a virtual DOM by describing the structure of VNode objects, the render function, the createElement process, and the normalization utilities, providing detailed code examples and step‑by‑step analysis of the rendering pipeline.
This article explains why micro frontends are needed, outlines their engineering and product benefits, describes key architectural requirements, shares practical decisions such as stack‑independent bootstrapping, routing, isolation, resource loading, and communication, and presents real‑world results from Ant Financial’s OneX platform.
This article walks through Vue's source code to explain how the new Vue constructor initializes a component, merges options, proxies data, mounts the instance, and ultimately replaces template interpolations with reactive data during the rendering process.
Xianyu created a highly extensible user‑behavior collection framework that standardizes data into a common ODPS schema, uses JavaScript Proxy to intercept navigation and API calls, maps business metrics via JSON, aggregates reports to cut dataset‑creation effort from days to minutes while avoiding heavy full‑tracking overhead.
This article explains two algorithmic solutions for locating any duplicate number in an array of length n where values range from 0 to n‑1: a straightforward HashSet method using O(n) extra space and an in‑place swapping technique that achieves O(1) space, complete with Java and JavaScript code examples and complexity analysis.
An in‑depth analysis of V8’s Inline Cache mechanism shows how hidden classes, map transitions, type‑feedback vectors, and the IC state machine cause the second invocation of a JavaScript constructor to be slower than the first, while the third becomes faster, explaining performance variations in property accesses.
This article introduces Chrome extension fundamentals, outlines its core components and APIs, and provides a step‑by‑step guide—including server‑side WebSocket handling, content‑script communication, popup QR‑code generation, and installation methods—to create a flip‑pen remote‑control plugin.
This article explains the technical principles and step‑by‑step implementation of QR‑code login, covering both the web‑client and server sides, with detailed examples from WeChat and Taobao, including request flows, Redis usage, token handling, and JavaScript code snippets.
During pandemic remote work, this guide shows engineers how to use a webcam, TensorFlow.js pose detection, and simple web APIs to monitor posture, automate meal and water reminders, and generate audio alerts, turning everyday health risks into a programmable personal wellness system.
This article demonstrates how to enhance Selenium web‑scraping scripts by using JavaScript to directly modify date picker values and to automatically scroll dynamic pages, providing concise code examples that overcome common challenges when crawling sites like 12306 and Tencent Video.
This article ranks the seven most popular programming languages for test automation in 2020—Python, Java, JavaScript, C#, Ruby, PHP, and SmashTest—detailing their strengths, community support, and key frameworks to help you select the best language for your automation projects.
This article explains how to create a long‑press button in a Vue application by using native JavaScript events, timers, and a custom Vue directive, covering variable setup, start and cancel functions, event listeners for mouse and touch, and error handling for non‑function bindings.
This guide walks you through the rationale for desktop (C/S) apps, introduces Electron, details environment setup, project scaffolding, source structure, main and renderer processes, and showcases complete example applications built with Electron‑Vue.
This article explains why Chinese web fonts are large, how to analyze their structure, and presents practical techniques—including fontmin subsetting, SVG rendering, and the FontFace API—to dramatically reduce load time and control font display behavior for better user experience.
This article explains why dark mode has become a web design focus, describes system‑level dark/light themes, and provides step‑by‑step CSS and JavaScript solutions—including media queries, custom properties, color‑scheme, filters, mix‑blend‑mode, image handling, and loading strategies—to implement reliable dark mode across browsers.
This article introduces the Quill rich‑text editor, explains its built‑in modules, details the toolbar module loading process, and walks through creating a custom counter module, providing code examples and configuration tips for extending Quill in frontend projects.
The article explains front‑end development as browser‑side code that renders HTML skeleton, CSS styling, and JavaScript interactivity, traces the full request‑to‑display lifecycle, recounts JavaScript’s history from 1995 to ES6, and surveys evolving paradigms such as Ajax, MVC, MVVM, SPA, SSR, and full‑stack Node.
This article explains why dark mode has become a web design priority, describes the system‑level nature of dark/light themes, and provides practical CSS and JavaScript solutions—including media queries, custom properties, color‑scheme, filters, mix‑blend‑mode, and transition effects—to implement seamless dark mode support across browsers.
This article chronicles Yuque's evolution from a 2016 internal prototype to a fully commercialized knowledge‑base platform, detailing its JavaScript full‑stack architecture, migration from BaaS to IaaS, adoption of microservices and serverless functions, and the security and stability practices that support its growth.
This article explains the middleware design pattern in JavaScript, illustrating recursive and chainable implementations with Koa and Redux, and explores techniques such as function composition, reduceRight, parameter passing, and the role of currying and closures.
The article outlines typical anti‑crawling measures such as browser detection, captchas, login requirements, JavaScript obfuscation, and behavior‑based blocks, and provides practical counter‑strategies including header spoofing, captcha solving, session/token handling, JS emulation, and human‑like request pacing.
This article explains the technical principles behind QR code login, detailing the client‑server interaction, UUID generation, Redis storage, long‑polling, and token handling, and illustrates the implementation with real‑world examples from Taobao and WeChat, including code snippets and flow diagrams.
This article explains the technical principles behind QR code login, detailing the interaction between web, mobile, and server components, and provides concrete implementation examples from Taobao and WeChat, including code snippets, request flows, and handling of various response states.
This article explains the technical principles behind QR‑code login, detailing the end‑to‑end workflow between browsers, mobile apps and servers, and provides concrete implementations from Taobao and WeChat, including code snippets, polling mechanisms, Redis usage, and error handling.
This tutorial walks through essential Selenium WebDriver techniques in Python, covering driver path configuration, capturing full and partial screenshots, page refresh methods, opening new tabs, cropping images with Pillow, executing JavaScript, and retrieving script results, all with clear code examples.
This article provides a clear, step‑by‑step tutorial on regular expressions—covering fundamental metacharacters, quantifiers, grouping, alternation, character classes, assertions, capturing, back‑references, greedy vs. lazy matching, and includes runnable code snippets in Java and JavaScript for common validation tasks.
This article surveys the ten most promising Chinese front‑end frameworks of 2019‑2020, such as Ramda, WeUI, ColorUI, Omi, Taro, Flutter, SpriteJS, NestJS, DoKit and imgcook, highlighting their origins, key features, ecosystem support and GitHub popularity to illustrate the rapid evolution of front‑end technology.
This week’s Front‑End roundup covers a visual page‑builder design, Canvas‑based image filters, a Vue vs React comparison, a 2019 technology review, Airbnb’s large‑scale GraphQL migration, and the latest ES2020 JavaScript features, each with concise insights and illustrative images.
This tutorial explains how to implement common image filters such as red, grayscale, and inverse effects using the Canvas API, then introduces convolution fundamentals to achieve advanced effects like edge detection and sharpening, complete with code samples and visual results.
This article explains how to create a Babel plugin that removes console calls in production builds while extending console methods with styled output and source location information in development, covering installation, configuration, AST manipulation, option validation, and comprehensive testing using TypeScript, ts‑mocha, and chai.
This guide presents a high‑level knowledge map for Vue developers, covering essential JavaScript basics, core Vue concepts, component architecture, SPA routing, state management, real‑world tooling, testing, performance optimization, related ecosystems, and advanced frameworks like Nuxt and Vuetify.
This tutorial walks through creating a lightweight web Gomoku game using JavaScript, detailing both a plain‑DOM renderer and a Canvas renderer, their interchangeable architecture, and core features like move handling, undo/redo, win detection, and board resetting.
This article explains the motivations behind Taro 2.0’s CLI overhaul, details how the custom build system was replaced by Webpack, provides step‑by‑step migration instructions, showcases new hooks, loader and plugin configurations, and outlines future plans for the framework.
This article provides a detailed walkthrough of Vue.js’s core initialization process, examining how the framework’s global API, asset registration, and various utility functions are set up through multiple layers of source code, with extensive code examples and explanations of each step.
This article explains how the spread operator combined with logical && can conditionally add properties to an object, detailing the underlying ECMAScript specification, the CopyDataProperties abstract operation, and edge cases with null, undefined, and primitive values.
This article explains why WeChat Mini Programs need a custom cookie solution, details the browser cookie model, and provides a step‑by‑step implementation using the Mini Program Storage and Network APIs, including code samples, performance tips, testing, and security considerations.
This guide explains how Laravel automatically generates CSRF tokens, how to embed them in Blade forms, configure the VerifyCsrfToken middleware, whitelist routes, and integrate token handling with JavaScript libraries such as Axios and jQuery for robust request protection.
This article chronicles a developer's transition from plain JavaScript to TypeScript, illustrating how static typing improves code robustness, debugging, and documentation while also discussing migration steps, common pitfalls, and practical examples across frontend projects.
This article walks through creating a JSON parser in JavaScript, covering the JSON grammar, railroad and BNF diagrams, step‑by‑step implementation of object, array and value parsing, robust error handling, and suggestions for meaningful error messages.
The 2019 frontend landscape saw React retain dominance, TypeScript surge, WebAssembly become a fourth web language, Vue prepare for version 3, Angular introduce Ivy, static sites and JAMstack rise, PWA adoption grow, and a wave of new tools, standards, and predictions for 2020, reflecting rapid evolution across frameworks, languages, and tooling.
This tutorial explains how to bring TypeScript‑style type checking and autocomplete into regular JavaScript files using VSCode, JSDoc comments, and declaration files, allowing developers to enjoy static‑type benefits without converting the whole project to .ts files.
Tencent’s open‑source Hippy framework, now used by 18 internal services with over a hundred million daily page views, offers a front‑end‑friendly, W3C‑compliant cross‑platform solution that supports React and Vue, reduces learning barriers, and improves performance through a C++‑based engine‑direct architecture.
This article details NetEase Yanxuan's enterprise micro‑frontend solution, covering its architectural design, isolation techniques, communication mechanisms, configuration center, and the concrete business benefits such as breaking down giant monoliths, improving module reuse, and streamlining multi‑team collaboration.
This article introduces ESLint, explains why JavaScript linting is essential, walks through installation, demonstrates sample code with common errors, shows how to configure rules via .eslintrc.js, and outlines IDE integration to improve frontend development efficiency.
This article surveys the evolution of JavaScript from ES5 through ES10, explains which features are native in modern browsers, outlines the stage‑process for proposals, showcases code examples for classes, modules, generators, async/await, optional chaining, and discusses whether Babel is still needed.
This article dissects the inner workings of React's useEffect hook by tracing its implementation through the React Fiber architecture, from mountEffect and updateEffect functions to the commit phase, revealing how side‑effects are scheduled, created, and cleaned up in modern React applications.
This article explains how to reverse a clockwise‑rotating Firefox logo animation by understanding the APNG file format, identifying frame chunks, and rewriting the binary data with JavaScript to play the frames in reverse order.
This article presents a curated list of 26 powerful Visual Studio Code extensions—including Project Snippets, Better Comments, Bracket Pair Colorizer, Material Theme, ESLint, Stylelint, REST Client, and many more—that enhance productivity, code quality, and workflow for JavaScript and TypeScript developers.
This article provides a detailed technical analysis of FLV.js and HLS.js architectures, explains their common media pipeline, and describes step‑by‑step how to combine them into a single JavaScript player that supports both live FLV streams and HLS replay on a PC web site.
This article examines why third‑party JavaScript often slows sites, explains the hidden costs of convenience, and provides a step‑by‑step mitigation plan—including responsibility assignment, self‑hosting, connection pre‑connect, and lazy‑loading techniques—to help developers improve web performance.
This article traces JavaScript’s evolution, covering the enrichment of prototype methods, standardization of classes and modules, the rise of asynchronous patterns like callbacks, promises, generators, async/await, and modern syntax features such as block scope, symbols, BigInt, reflection, and useful syntactic sugar.
This article explains why a newly rebuilt site can suffer a “JavaScript hangover,” then walks through concrete front‑end performance techniques—including tree shaking, code splitting, externalizing third‑party scripts, smaller library choices, differential serving, and reducing Babel‑generated bloat—to restore speed and improve user experience.
This article explains the concept, types, lifecycle, and security considerations of HTTP cookies, illustrates how browsers store and send cookies, describes the cookie‑jar model, domain handling, and related CORS mechanisms, and provides practical JavaScript examples.
The guide shows how to modify a Webpack‑4 JavaScript SDK—adding Babel symbol handling, using transform‑runtime, employing Flash for IE9 cross‑domain requests, converting ES5 to ES3 with es3ify‑loader, configuring UglifyJs for IE8, polyfilling missing APIs, building a tiny selector engine, and testing on virtual IE7‑IE9 machines.
The article describes how to enforce architectural rules and assess change impact in a modularized JavaScript application by extracting import statements via AST, building a file‑map, constructing a cycle‑aware dependency graph with indexed nodes, and traversing it with a visited‑stack to support forward and reverse analysis across business and public bundles.
JavaScript’s growing size threatens web performance and accessibility, so developers must evaluate when to use frameworks, adopt progressive enhancement, reduce unnecessary code, and leverage native browser features like prefetch and service workers to build faster, more sustainable, and inclusive web experiences.
This article introduces Sketchify, a JavaScript tool built on RoughJS that transforms any SVG‑based chart into a hand‑drawn sketch style, explains its underlying algorithm, provides sample code, demonstrates its application to popular libraries such as ECharts, AntV G2, Highcharts, amCharts and xCharts, and discusses its limitations and resource considerations.
Vue 3 replaces Vue 2’s Object.defineProperty reactivity with a Proxy‑based system, using the Composition API (e.g., a reusable usePosition hook) to create reactive state, cache proxies via WeakMaps, differentiate array additions from length changes, and track dependencies through effect stacks for efficient updates.
This comprehensive guide explores the Intersection Observer API, explaining its core concepts, detailed code examples, performance comparisons with scroll events, advanced usage like sticky positioning, visibility tracking, and browser compatibility, providing developers with practical insights to efficiently implement and optimize intersection-based interactions.
This tutorial walks through creating a web‑based server monitoring tool that tracks CPU load and disk usage, using Vue.js with Element UI and Echarts for the frontend and a Python Flask backend with SQLite for data storage and API delivery.
This article thoroughly dissects JavaScript Promise execution, revealing how microtasks are registered and run across multiple code snippets, compares Promise/A+ with WebKit implementations, and provides detailed code analyses and output predictions to help developers master Promise behavior.
This guide walks you through Sketch plugin architecture, manifest configuration, command definitions, Actions and JavaScript APIs, CocoaScript bridging, UI panel creation with AppKit, sidebar navigation, debugging techniques, logging methods, and using SketchTool for automation, providing practical code examples for each step.
This article explains how Google's V8 engine parses JavaScript, distinguishes eager and lazy parsing, inlines functions, manages object hidden classes, and offers practical optimization tips to improve runtime performance in Chrome, Node.js, and Edge.
This article explains how Vue 3.0 rewrites its reactivity system using Proxy and Reflet, introduces the reactive, effect, and computed APIs, compares them with MobX, and details the resulting changes for arrays, collections, lazy observation, and IE compatibility.
This tutorial walks through constructing a JavaScript arithmetic parser using a finite‑state lexer, a stack‑based parser that builds an abstract syntax tree (AST), and an evaluator that supports numbers, operators, parentheses, vectors, and custom symbols like @rot and @dot, complete with visual demos.
This guide explains how the mongoose-modified-at plugin automatically records publication timestamps for MongoDB documents, covering installation, schema configuration, API options, simplified usage, async support, compatibility with Mongoose 4.x, and test‑coverage details.
This article explains how to emulate Vue's computed properties in React by extracting calculations from the render method, using class getters, applying memoization with memoize-one, and leveraging the useMemo hook to achieve dependency‑based caching and cleaner component code.
The weekly roundup presents concise, actionable articles on font fundamentals, building an AST for arithmetic expressions, cyclomatic complexity metrics, the evolution from HTTP/2 to HTTP/3, native image lazy‑loading, and an overview of CSS Level‑4 selectors, all aimed at front‑end engineers.
This article explains how to implement a lexical analyzer in JavaScript that tokenizes simple arithmetic expressions by using a finite state machine, covering the conversion from infix notation to an abstract syntax tree, token definitions, state transitions, and complete source code examples.
This article explains how to use localStorage, sessionStorage, and the storage event to achieve reliable, side‑effect‑free data synchronization between same‑origin web pages, providing a practical implementation with JavaScript code and detailed design considerations.
WebAssembly enables high‑performance, ahead‑of‑time compiled code to run in browsers, and iQIYI leverages it by writing a C‑based FLV‑to‑MP4 transcoder compiled to Wasm, executed in a Web Worker, which boosts live‑stream conversion speed, reduces CPU usage, and opens doors for further web‑based media processing.
This article explains how to transform raw HTML strings into a structured abstract syntax tree (AST) using JavaScript regular expressions and a step‑by‑step parsing algorithm, covering tag, attribute, and text node handling, with a complete example implementation of a lightweight AST parser.
This article introduces IndexedDB as a client‑side non‑relational database, explains its core concepts and API objects, and provides a step‑by‑step code example for creating, reading, updating, and deleting records, while also recommending helper libraries to simplify development.
This article analyzes the open‑source portfolios of Alibaba, Baidu and Tencent, showing how many projects each company has, the proportion that have been abandoned, language distribution, and the top‑10 abandoned projects by stars, contributors and commits, based on GitHub data up to March 2019.
This article describes how Ctrip's marketing team built the Legao platform—a visual, component‑based front‑end system that enables rapid configuration of thousands of activity pages through reusable business, web, and activity‑level components, detailing its architecture, technology stack, SDK, and dynamic form system.
This article explains how to use Puppeteer to automate interactions with non‑DOM canvas objects in KuJiaLe's web‑based design tools, detailing the underlying API, the automation framework setup, and a step‑by‑step demo of moving a bedroom bed.
This comprehensive guide explains why TypeScript has surpassed JavaScript in popularity, introduces its core concepts, basic and advanced types, generics, interfaces, classes, and modules, and provides step‑by‑step instructions for integrating TypeScript into both frontend and Node.js projects.
This article walks through creating a lightweight Mocha‑like testing framework in JavaScript, covering BDD‑style APIs, directory layout, suite and test class design, hook handling, asynchronous support, a runner that traverses the suite‑test tree, and a reporter that outputs test results.
