JavaScript terms
🤖 AI Guestbook — JavaScript educational data only
|
|
Last 30 days
Agents 30
Claude 27SEMrush 2PetalBot 1
PetalBot 15SEMrush 6Bing 4Ahrefs 2Google 2Perplexity 1Sogou 1ChatGPT 1
Amazonbot 789Scrapy 691Perplexity 518Google 478ChatGPT 402Ahrefs 334Unknown AI 251SEMrush 251Claude 146Majestic 142Meta AI 114Bing 85PetalBot 47Sogou 18Qwen 17DuckDuckGo 6ShapBot 4Common Crawl 3LinkedIn 2
Most referenced — JavaScript
AJAX Patterns for PHP Backends 3ReferenceError — Undefined Variables 2Web Components 2ES6 Class Syntax 1Accidental Object Mutation Bugs 1Object.freeze / Object.seal 1Array.flat() & Array.flatMap() 1Clipboard API 1
How they use it
crawler 3.9k
crawler_json 303
pre-tracking 105
Category total4.3k pings
Terms pinged97 / 97
Distinct agents18
Promise.allSettled / Promise.any / Promise.race
ES2020
Three Promise combinators for handling multiple async operations — allSettled() waits for all to complete regardless of failure, any() resolves with the first success, race() resolves or rejects with the first to settle.
3mo ago
JavaScript intermediate
requestAnimationFrame — Smooth Animations
HTML5
requestAnimationFrame(callback) schedules a function to run before the browser's next repaint — the correct way to animate in JavaScript, producing smooth 60fps motion and automatically pausing when the tab is hidden.
3mo ago
JavaScript intermediate
ResizeObserver API
HTML5
ResizeObserver watches element size changes without polling — more efficient than resize event listeners and works for any element, not just the window.
3mo ago
JavaScript intermediate
Scheduler API (scheduler.postTask)
ES2021
The Scheduler API (scheduler.postTask) lets you prioritise async tasks — user-blocking, user-visible, or background — giving the browser hints to schedule work optimally.
3mo ago
JavaScript advanced
Streams API — ReadableStream & WritableStream
HTML5
4
The Streams API provides composable, backpressure-aware data pipelines in the browser — processing large responses, files, or media chunk by chunk without buffering everything in memory.
3mo ago
JavaScript advanced
Top-Level Await in Modules
ES2022
ES2022 top-level await lets you use await at the module root without wrapping in async function — blocking module evaluation until the awaited Promise resolves.
3mo ago
JavaScript intermediate
toSorted / toReversed / with — Immutable Array Methods
ES2023
1
JavaScript ES2023 adds immutable counterparts to mutating array methods: toSorted() returns a sorted copy, toReversed() returns a reversed copy, and with(index, value) returns a copy with one element replaced — none mutate the original array.
3mo ago
JavaScript beginner
Web Locks API — Coordinating Across Tabs
HTML5
The Web Locks API lets JavaScript in the same origin coordinate exclusive or shared access to a named resource across multiple tabs, workers, or iframes — a browser-native mutex.
3mo ago
JavaScript intermediate
Web Share API
HTML5
1
navigator.share() invokes the native OS share sheet on mobile — letting users share URLs, text, and files via any app installed on their device.
3mo ago
JavaScript beginner
Accidental Object Mutation Bugs
ES2015
Objects and arrays are passed by reference in JS — mutating a function parameter or array element mutates the original, causing subtle cross-component state bugs.
3mo ago
JavaScript intermediate
Async Error Handling (try/catch + Promise)
ES2017
1
Errors in async functions require try/catch or .catch() — a rejected Promise that's not caught becomes an unhandledRejection that crashes Node or shows a console warning in browsers.
3mo ago
JavaScript intermediate
Classic Closure-in-Loop Bug (var vs let)
ES2015
The most common JavaScript closure bug: using var in a for loop captures the loop variable by reference so all callbacks see the final value — fixed by using let which creates a new binding per iteration.
3mo ago
JavaScript intermediate
Event Loop Blocking — Long Tasks
ES5
JavaScript is single-threaded — synchronous code that runs >50ms blocks the event loop, freezing UI and delaying I/O callbacks. Break long tasks into chunks.
3mo ago
JavaScript intermediate
Hoisting — var, let, const and function
ES5
JavaScript hoists declarations to the top of their scope — var and function declarations are fully hoisted, while let and const are hoisted but remain in the Temporal Dead Zone until their declaration line.
3mo ago
JavaScript intermediate
Implicit Globals & strict mode
ES5
Assigning to an undeclared variable in non-strict mode silently creates a global — use 'use strict' or ES modules to prevent accidental global pollution.
3mo ago
JavaScript intermediate
Memory Leaks — Closures, Detached DOM
ES2015
JavaScript memory leaks occur when references are accidentally retained — common causes: closures holding large objects, detached DOM nodes, forgotten event listeners, and growing Maps/Sets.
3mo ago
JavaScript advanced
NaN — Detection & Avoiding Pitfalls
ES2015
NaN is the only JavaScript value not equal to itself — use Number.isNaN() (not isNaN()) to detect it, as isNaN() coerces its argument first.
3mo ago
JavaScript beginner
Prototype Chain Errors & hasOwnProperty
ES2022
Iterating objects with for...in includes inherited prototype properties — use hasOwnProperty() or Object.keys() to iterate only own properties.
3mo ago
JavaScript intermediate
ReferenceError — Undefined Variables
ES2015
ReferenceError is thrown when accessing a variable that hasn't been declared — unlike undefined which is a declared variable with no value.
3mo ago
JavaScript beginner
SyntaxError — Parse-Time Failures
ES5
SyntaxError means JavaScript couldn't parse your code — the entire script fails to execute. Common causes: missing brackets, invalid JSON, reserved word misuse.
3mo ago
JavaScript beginner