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Reference

Quick-lookup documentation for JavaScript's built-in objects, methods, and APIs.

Array Methods

Methods available on every JavaScript Array instance.

Array..from() Array..isArray() Array..of() Array.at() Array.concat() Array.copyWithin() Array.entries() Array.every() Array.fill() Array.filter() Array.find() Array.findIndex() Array.findLast() Array.findLastIndex() Array.flat() Array.flatMap() Array.includes() Array.indexOf() Array.join() Array.keys() Array.lastIndexOf() Array.map() Array.pop() Array.push() Array.reduce() Array.reduceRight() Array.shift() Array.some() Array.splice() Array.toReversed() Array.toSorted() Array.toSpliced() Array.toString() Array.unshift() Array.values() Array.with()

Async APIs

Promise-based APIs and async patterns.

fetch() Promise Promise.all() Promise.allSettled() Promise.any() Promise.catch() Promise.finally() Promise.then() Promise.race() Promise.reject() Promise.resolve()

Built-in Objects

Core objects available in every JavaScript environment.

AbortController ArrayBuffer BigInt console Date Error Object RegExp Symbol TypedArray

Global Functions

Top-level functions available in every JavaScript environment.

decodeURI() decodeURIComponent() encodeURI() encodeURIComponent() eval() isNaN() parseFloat() parseInt() structuredClone()

JSON

JSON parsing and stringification.

JSON.isRawJSON() JSON.parse() JSON.stringify()

Map and Set

Map, Set, WeakMap, and WeakSet collection types.

Map Map.clear() Map.delete() Map.entries() Map.forEach() Map.get() Map.has() Map.keys() Map.set() Map.values() Set Set.add() Set.clear() Set.delete() Set.entries() Set.forEach() Set.has() Set.keys() Set.size Set.values() WeakMap WeakSet

Math

Math object for mathematical functions and constants.

Math.abs() Math.ceil() Math.clz32() Math.E Math.exp() Math.floor() Math.fround() Math.LN10 Math.LN2 Math.log() Math.log10() Math.LOG10E Math.log1p() Math.log2() Math.LOG2E Math.max() Math.min() Math.PI Math.pow() Math.round() Math.sign() Math.sqrt() Math.SQRT1_2 Math.SQRT2 Math.trunc()

Node.js Modules

Core Node.js modules and APIs.

Buffer child_process module crypto module events module fs module fs/promises module node:http node:https node:url os module path module process readline module stream

Number

Number type, constants, and parsing functions.

Number.isFinite() Number.isInteger() Number.isNaN() Number.toFixed() Number.toPrecision() Number.toString()

Object Methods

Static methods on the Object constructor.

Object.assign() Object.create() Object.defineProperty() Object.entries() Object.freeze() Object.fromEntries() Object.getPrototypeOf() Object.hasOwn() Object.is() Object.keys() Object.seal() Object.setPrototypeOf()

String Methods

Methods available on every JavaScript String instance.

String.fromCodePoint() String..substring() String.at() String.charAt() String.charCodeAt() String.codePointAt() String.concat() String.endsWith() String.includes() String.indexOf() String.lastIndexOf() String.localeCompare() String.match() String.matchAll() String.normalize() String.padEnd() String.padStart() String.repeat() String.replace() String.replaceAll() String.search() String.slice() String.split() String.startsWith() String.toLowerCase() String.toUpperCase() String.trim() String.trimEnd() String.trimStart()