JavaScript Reference

Articles

JavaScript Reference

The JavaScript reference serves as a repository of facts about the JavaScript language. The entire language is described here in detail.

JavaScript pages

A

A re-introduction to JavaScript (JS tutorial)

About JavaScript

About this reference

Additional examples for Object.defineProperty

Arguments object

arguments.callee

arguments.caller

arguments.length

arguments[@@iterator]()

Arithmetic operators

Arithmetic operators

Array comprehensions

Array.isArray()

Array.observe()

Array.prototype

Array.prototype.concat()

Array.prototype.copyWithin()

Array.prototype.entries()

Array.prototype.every()

Array.prototype.fill()

Array.prototype.filter()

Array.prototype.find()

Array.prototype.findIndex()

Array.prototype.forEach()

Array.prototype.includes()

Array.prototype.indexOf()

Array.prototype.join()

Array.prototype.keys()

Array.prototype.lastIndexOf()

Array.prototype.map()

Array.prototype.pop()

Array.prototype.push()

Array.prototype.reduce()

Array.prototype.reduceRight()

Array.prototype.reverse()

Array.prototype.shift()

Array.prototype.slice()

Array.prototype.some()

Array.prototype.sort()

Array.prototype.splice()

Array.prototype.toLocaleString()

Array.prototype.toSource()

Array.prototype.toString()

Array.prototype.unshift()

Array.prototype.values()

Array.prototype[@@iterator]()

Array.prototype[@@unscopables]

Array.unobserve()

ArrayBuffer.isView()

ArrayBuffer.prototype

ArrayBuffer.prototype.byteLength

ArrayBuffer.prototype.slice()

ArrayBuffer.transfer()

ArrayBufferView

Arrow functions

Assignment operators

Atomics.compareExchange()

Atomics.exchange()

Atomics.isLockFree()

Atomics.store()

B

Base64 encoding and decoding

Bitwise operators

Boolean.prototype

Boolean.prototype.toSource()

Boolean.prototype.toString()

Boolean.prototype.valueOf()

C

class expression

Comparison operators

Concurrency model and Event Loop

Conditional (ternary) Operator

Control flow and error handling

D

DataView.prototype

DataView.prototype.buffer

DataView.prototype.byteLength

DataView.prototype.byteOffset

DataView.prototype.getFloat32()

DataView.prototype.getFloat64()

DataView.prototype.getInt16()

DataView.prototype.getInt32()

DataView.prototype.getInt8()

DataView.prototype.getUint16()

DataView.prototype.getUint32()

DataView.prototype.getUint8()

DataView.prototype.setFloat32()

DataView.prototype.setFloat64()

DataView.prototype.setInt16()

DataView.prototype.setInt32()

DataView.prototype.setInt8()

DataView.prototype.setUint16()

DataView.prototype.setUint32()

DataView.prototype.setUint8()

Date.prototype.getDate()

Date.prototype.getDay()

Date.prototype.getFullYear()

Date.prototype.getHours()

Date.prototype.getMilliseconds()

Date.prototype.getMinutes()

Date.prototype.getMonth()

Date.prototype.getSeconds()

Date.prototype.getTime()

Date.prototype.getTimezoneOffset()

Date.prototype.getUTCDate()

Date.prototype.getUTCDay()

Date.prototype.getUTCFullYear()

Date.prototype.getUTCHours()

Date.prototype.getUTCMilliseconds()

Date.prototype.getUTCMinutes()

Date.prototype.getUTCMonth()

Date.prototype.getUTCSeconds()

Date.prototype.getYear()

Date.prototype.setDate()

Date.prototype.setFullYear()

Date.prototype.setHours()

Date.prototype.setMilliseconds()

Date.prototype.setMinutes()

Date.prototype.setMonth()

Date.prototype.setSeconds()

Date.prototype.setTime()

Date.prototype.setUTCDate()

Date.prototype.setUTCFullYear()

Date.prototype.setUTCHours()

Date.prototype.setUTCMilliseconds()

Date.prototype.setUTCMinutes()

Date.prototype.setUTCMonth()

Date.prototype.setUTCSeconds()

Date.prototype.setYear()

Date.prototype.toDateString()

Date.prototype.toGMTString()

Date.prototype.toISOString()

Date.prototype.toJSON()

Date.prototype.toLocaleDateString()

Date.prototype.toLocaleFormat()

Date.prototype.toLocaleString()

Date.prototype.toLocaleTimeString()

Date.prototype.toSource()

Date.prototype.toString()

Date.prototype.toTimeString()

Date.prototype.toUTCString()

Date.prototype.valueOf()

Date.prototype[@@toPrimitive]

decodeURIComponent()

Default parameters

delete operator

Deprecated and obsolete features

Destructuring assignment

Details of the object model

E

ECMAScript 5 support in Mozilla

ECMAScript 6 support in Mozilla

ECMAScript Next support in Mozilla

encodeURIComponent()

Enumerability and ownership of properties

Equality comparisons and sameness

Error.prototype

Error.prototype.columnNumber

Error.prototype.fileName

Error.prototype.lineNumber

Error.prototype.message

Error.prototype.name

Error.prototype.stack

Error.prototype.toSource()

Error.prototype.toString()

Error: Permission denied to access property "x"

EvalError.prototype

Expression closures

Expressions and operators

Expressions and operators

F

Firefox JavaScript changelog

function expression

function* expression

Function.arguments

Function.caller

Function.displayName

Function.length

Function.prototype

Function.prototype.apply()

Function.prototype.bind()

Function.prototype.call()

Function.prototype.isGenerator()

Function.prototype.toSource()

Function.prototype.toString()

G

Generator comprehensions

Generator.prototype.next()

Generator.prototype.return()

Generator.prototype.throw()

GeneratorFunction

GeneratorFunction.prototype

get Array[@@species]

get ArrayBuffer[@@species]

get Map[@@species]

get RegExp[@@species]

get Set[@@species]

get TypedArray[@@species]

Grammar and types

Grouping operator

H

handler.apply()

handler.construct()

handler.defineProperty()

handler.deleteProperty()

handler.enumerate()

handler.getOwnPropertyDescriptor()

handler.getPrototypeOf()

handler.isExtensible()

handler.ownKeys()

handler.preventExtensions()

handler.setPrototypeOf()

I

Indexed collections

Inheritance and the prototype chain

InternalError.prototype

InternalError: too much recursion

Intl.Collator.prototype

Intl.Collator.prototype.compare

Intl.Collator.prototype.resolvedOptions()

Intl.Collator.supportedLocalesOf()

Intl.DateTimeFormat

Intl.DateTimeFormat.prototype

Intl.DateTimeFormat.prototype.format

Intl.DateTimeFormat.prototype.formatToParts()

Intl.DateTimeFormat.prototype.resolvedOptions()

Intl.DateTimeFormat.supportedLocalesOf()

Intl.getCanonicalLocales()

Intl.NumberFormat

Intl.NumberFormat.prototype

Intl.NumberFormat.prototype.format

Intl.NumberFormat.prototype.resolvedOptions()

Intl.NumberFormat.supportedLocalesOf()

Introduction to Object-Oriented JavaScript

Iteration protocols

Iterators and generators

J

JavaScript data types and data structures

JavaScript error reference

JavaScript Guide

JavaScript language resources

JavaScript methods index

JavaScript properties index

JavaScript reference

JavaScript shells

JavaScript technologies overview

JavaScript typed arrays

JSON.stringify()

K

Keyed collections

L

Legacy generator function

Legacy generator function expression

Lexical grammar

Lexical grammar

Logical Operators

Loops and iteration

M

Map.prototype.clear()

Map.prototype.delete()

Map.prototype.entries()

Map.prototype.forEach()

Map.prototype.get()

Map.prototype.has()

Map.prototype.keys()

Map.prototype.set()

Map.prototype.size

Map.prototype.values()

Map.prototype[@@iterator]()

Map.prototype[@@toStringTag]

Memory Management

Meta programming

Method definitions

N

New in JavaScript

New in JavaScript 1.1

New in JavaScript 1.2

New in JavaScript 1.3

New in JavaScript 1.4

New in JavaScript 1.5

New in JavaScript 1.6

New in JavaScript 1.7

New in JavaScript 1.8

New in JavaScript 1.8.1

New in JavaScript 1.8.5

Number.isFinite()

Number.isInteger()

Number.isSafeInteger()

Number.MAX_SAFE_INTEGER

Number.MAX_VALUE

Number.MIN_SAFE_INTEGER

Number.MIN_VALUE

Number.NEGATIVE_INFINITY

Number.parseFloat()

Number.parseInt()

Number.POSITIVE_INFINITY

Number.prototype

Number.prototype.toExponential()

Number.prototype.toFixed()

Number.prototype.toLocaleString()

Number.prototype.toPrecision()

Number.prototype.toSource()

Number.prototype.toString()

Number.prototype.valueOf()

Number.toInteger()

Numbers and dates

O

Object initializer

Object.assign()

Object.create()

Object.defineProperties()

Object.defineProperty()

Object.entries()

Object.freeze()

Object.getNotifier()

Object.getOwnPropertyDescriptor()

Object.getOwnPropertyDescriptors()

Object.getOwnPropertyNames()

Object.getOwnPropertySymbols()

Object.getPrototypeOf()

Object.isExtensible()

Object.isFrozen()

Object.isSealed()

Object.observe()

Object.preventExtensions()

Object.prototype

Object.prototype.__count__

Object.prototype.__defineGetter__()

Object.prototype.__defineSetter__()

Object.prototype.__lookupGetter__()

Object.prototype.__lookupSetter__()

Object.prototype.__noSuchMethod__

Object.prototype.__parent__

Object.prototype.__proto__

Object.prototype.constructor

Object.prototype.eval()

Object.prototype.hasOwnProperty()

Object.prototype.isPrototypeOf()

Object.prototype.propertyIsEnumerable()

Object.prototype.toLocaleString()

Object.prototype.toSource()

Object.prototype.toString()

Object.prototype.unwatch()

Object.prototype.valueOf()

Object.prototype.watch()

Object.setPrototypeOf()

Object.unobserve()

Object.values()

Operator precedence

P

Promise.prototype

Promise.prototype.catch()

Promise.prototype.then()

Promise.reject()

Promise.resolve()

Property accessors

Proxy.revocable()

R

RangeError.prototype

RangeError: argument is not a valid code point

RangeError: invalid array length

RangeError: precision is out of range

RangeError: radix must be an integer

RangeError: repeat count must be less than infinity

RangeError: repeat count must be non-negative

ReferenceError.prototype

ReferenceError: "x" is not defined

ReferenceError: assignment to undeclared variable "x"

ReferenceError: deprecated caller or arguments usage

ReferenceError: invalid assignment left-hand side

ReferenceError: reference to undefined property "x"

Reflect.apply()

Reflect.construct()

Reflect.defineProperty()

Reflect.deleteProperty()

Reflect.enumerate()

Reflect.getOwnPropertyDescriptor()

Reflect.getPrototypeOf()

Reflect.isExtensible()

Reflect.ownKeys()

Reflect.preventExtensions()

Reflect.setPrototypeOf()

RegExp.input ($_)

regexp.lastIndex

RegExp.lastMatch ($&)

RegExp.lastParen ($+)

RegExp.leftContext ($`)

RegExp.prototype

RegExp.prototype.compile()

RegExp.prototype.exec()

RegExp.prototype.flags

RegExp.prototype.global

RegExp.prototype.ignoreCase

RegExp.prototype.multiline

RegExp.prototype.source

RegExp.prototype.sticky

RegExp.prototype.test()

RegExp.prototype.toSource()

RegExp.prototype.toString()

RegExp.prototype.unicode

RegExp.prototype[@@match]()

RegExp.prototype[@@replace]()

RegExp.prototype[@@search]()

RegExp.prototype[@@split]()

RegExp.rightContext ($')

Regular Expressions

Rest parameters

S

Set.prototype.add()

Set.prototype.clear()

Set.prototype.delete()

Set.prototype.entries()

Set.prototype.forEach()

Set.prototype.has()

Set.prototype.size

Set.prototype.values()

Set.prototype[@@iterator]()

SharedArrayBuffer

SharedArrayBuffer.prototype

SharedArrayBuffer.prototype.byteLength

SIMD.%type%.abs()

SIMD.%type%.add()

SIMD.%type%.addSaturate()

SIMD.%type%.allTrue()

SIMD.%type%.and()

SIMD.%type%.anyTrue()

SIMD.%type%.check()

SIMD.%type%.div()

SIMD.%type%.equal()

SIMD.%type%.extractLane()

SIMD.%type%.fromFloat32x4()

SIMD.%type%.fromFloat32x4Bits()

SIMD.%type%.fromFloat64x2Bits()

SIMD.%type%.fromInt16x8Bits()

SIMD.%type%.fromInt32x4()

SIMD.%type%.fromInt32x4Bits()

SIMD.%type%.fromInt8x16Bits()

SIMD.%type%.fromUint16x8Bits()

SIMD.%type%.fromUint32x4()

SIMD.%type%.fromUint32x4Bits()

SIMD.%type%.fromUint8x16Bits()

SIMD.%type%.greaterThan()

SIMD.%type%.greaterThanOrEqual()

SIMD.%type%.lessThan()

SIMD.%type%.lessThanOrEqual()

SIMD.%type%.load()

SIMD.%type%.max()

SIMD.%type%.maxNum()

SIMD.%type%.min()

SIMD.%type%.minNum()

SIMD.%type%.mul()

SIMD.%type%.neg()

SIMD.%type%.not()

SIMD.%type%.notEqual()

SIMD.%type%.or()

SIMD.%type%.prototype.toSource()

SIMD.%type%.prototype.toString()

SIMD.%type%.prototype.valueOf()

SIMD.%type%.reciprocalApproximation()

SIMD.%type%.reciprocalSqrtApproximation()

SIMD.%type%.replaceLane()

SIMD.%type%.select()

SIMD.%type%.shiftLeftByScalar()

SIMD.%type%.shiftRightByScalar()

SIMD.%type%.shuffle()

SIMD.%type%.splat()

SIMD.%type%.sqrt()

SIMD.%type%.store()

SIMD.%type%.sub()

SIMD.%type%.subSaturate()

SIMD.%type%.swizzle()

SIMD.%type%.xor()

Standard built-in objects

Statements and declarations

String.fromCharCode()

String.fromCodePoint()

String.prototype

String.prototype.anchor()

String.prototype.big()

String.prototype.blink()

String.prototype.bold()

String.prototype.charAt()

String.prototype.charCodeAt()

String.prototype.codePointAt()

String.prototype.concat()

String.prototype.endsWith()

String.prototype.fixed()

String.prototype.fontcolor()

String.prototype.fontsize()

String.prototype.includes()

String.prototype.indexOf()

String.prototype.italics()

String.prototype.lastIndexOf()

String.prototype.link()

String.prototype.localeCompare()

String.prototype.match()

String.prototype.normalize()

String.prototype.padEnd()

String.prototype.padStart()

String.prototype.quote()

String.prototype.repeat()

String.prototype.replace()

String.prototype.search()

String.prototype.slice()

String.prototype.small()

String.prototype.split()

String.prototype.startsWith()

String.prototype.strike()

String.prototype.sub()

String.prototype.substr()

String.prototype.substring()

String.prototype.sup()

String.prototype.toLocaleLowerCase()

String.prototype.toLocaleUpperCase()

String.prototype.toLowerCase()

String.prototype.toSource()

String.prototype.toString()

String.prototype.toUpperCase()

String.prototype.trim()

String.prototype.trimLeft()

String.prototype.trimRight()

String.prototype.valueOf()

String.prototype[@@iterator]()

Symbol.hasInstance

Symbol.isConcatSpreadable

Symbol.iterator

Symbol.keyFor()

Symbol.prototype

Symbol.prototype.toSource()

Symbol.prototype.toString()

Symbol.prototype.valueOf()

Symbol.prototype[@@toPrimitive]

Symbol.toPrimitive

Symbol.unscopables

SyntaxError.prototype

SyntaxError: "x" is not a legal ECMA-262 octal constant

SyntaxError: JSON.parse: bad parsing

SyntaxError: Malformed formal parameter

SyntaxError: missing ) after argument list

SyntaxError: missing ; before statement

SyntaxError: missing ] after element list

SyntaxError: missing } after property list

SyntaxError: redeclaration of formal parameter "x"

SyntaxError: return not in function

SyntaxError: test for equality (==) mistyped as assignment (=)?

SyntaxError: Unexpected token

SyntaxError: unterminated string literal

SyntaxError: Using //@ to indicate sourceURL pragmas is deprecated. Use //# instead

T

Template literals

Text formatting

The legacy Iterator protocol

The performance hazards of [[Prototype]] mutation

Transitioning to strict mode

TypedArray.BYTES_PER_ELEMENT

TypedArray.from()

TypedArray.name

TypedArray.of()

TypedArray.prototype

TypedArray.prototype.buffer

TypedArray.prototype.byteLength

TypedArray.prototype.byteOffset

TypedArray.prototype.copyWithin()

TypedArray.prototype.entries()

TypedArray.prototype.every()

TypedArray.prototype.fill()

TypedArray.prototype.filter()

TypedArray.prototype.find()

TypedArray.prototype.findIndex()

TypedArray.prototype.forEach()

TypedArray.prototype.includes()

TypedArray.prototype.indexOf()

TypedArray.prototype.join()

TypedArray.prototype.keys()

TypedArray.prototype.lastIndexOf()

TypedArray.prototype.length

TypedArray.prototype.map()

TypedArray.prototype.move()

TypedArray.prototype.reduce()

TypedArray.prototype.reduceRight()

TypedArray.prototype.reverse()

TypedArray.prototype.set()

TypedArray.prototype.slice()

TypedArray.prototype.some()

TypedArray.prototype.sort()

TypedArray.prototype.subarray()

TypedArray.prototype.values()

TypedArray.prototype[@@iterator]()

TypeError.prototype

TypeError: "x" has no properties

TypeError: "x" is (not) "y"

TypeError: "x" is not a constructor

TypeError: "x" is not a function

TypeError: "x" is read-only

TypeError: invalid Array.prototype.sort argument

TypeError: More arguments needed

TypeError: property "x" is non-configurable and can't be deleted

TypeError: variable "x" redeclares argument

U

Uint8ClampedArray

URIError.prototype

V

W

Warning: -file- is being assigned a //# sourceMappingURL, but already has one

Warning: JavaScript 1.6's for-each-in loops are deprecated

Warning: unreachable code after return statement

WeakMap.prototype

WeakMap.prototype.clear()

WeakMap.prototype.delete()

WeakMap.prototype.get()

WeakMap.prototype.has()

WeakMap.prototype.set()

WeakSet.prototype

WeakSet.prototype.add()

WeakSet.prototype.clear()

WeakSet.prototype.delete()

WeakSet.prototype.has()

Working with objects

Y