JavaScript reference

This part of the JavaScript section on MDN serves as a repository of facts about the JavaScript language. Read more about this reference.

JavaScript standard built-in objects, along with their methods and properties.

• Value properties

  Infinity
NaN
undefined
globalThis

• Function properties

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

• Fundamental objects

  Object
Function
Boolean
Symbol

• Error objects

  Error
AggregateError
EvalError
InternalError
RangeError
ReferenceError
SyntaxError
TypeError
URIError

• Numbers & dates

  Number
BigInt
Math
Date

• Text processing

  String
RegExp

• Indexed Collections Array
Int8Array
Uint8Array
Uint8ClampedArray
Int16Array
Uint16Array
Int32Array
Uint32Array
Float32Array
Float64Array
BigInt64Array
BigUint64Array
• Keyed collections

  Map
Set
WeakMap
WeakSet

• Structured data

  ArrayBuffer
SharedArrayBuffer
Atomics
DataView
JSON

• Control abstraction

  Promise
Generator
GeneratorFunction
AsyncFunction

• Reflection

  Reflect
Proxy

• Internationalization

  Intl
Intl.Collator
Intl.DateTimeFormat
Intl.DisplayNames
Intl.ListFormat
Intl.Locale
Intl.NumberFormat
Intl.PluralRules
Intl.RelativeTimeFormat

• WebAssembly

  WebAssembly
WebAssembly.Module
WebAssembly.Instance
WebAssembly.Memory
WebAssembly.Table
WebAssembly.CompileError
WebAssembly.LinkError
WebAssembly.RuntimeError

JavaScript statements and declarations

• Control flowBlock
break
continue
Empty
if...else
switch
throw
try...catch
• Declarations

  var
let
const

• Functions and classes

  function
function*
async function
return
class

• Iterations

  do...while
for
for each...in
for...in
for...of
for await...of
while

• Other

  debugger
import
label
with

JavaScript expressions and operators. 

This chapter documents how to work with JavaScript functions to develop your applications.

• arguments
• Arrow functions
• Default parameters
• Rest parameters

• Lexical grammar
• Data types and data structures
• Strict mode
• Deprecated features