So I have been writing about JavaScript for some time now, I also help a few of my friends learn JavaScript as they want to get into front end development. This is one of the personal favorite topics, but I was a bit surprised to find how many times, people get it wrong.
The problem with JS is that it doesn’t follow the general pattern like other languages. For e.g. in C#, the ref…
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.Built-ins
Value properties
Function properties
- eval()
- isFinite()
- isNaN()
- parseFloat()
- parseInt()
- decodeURI()
- decodeURIComponent()
- encodeURI()
- encodeURIComponent()
Fundamental objects
- Object
- Function
- Boolean
- Symbol
Error objects
- Error
- EvalError
- RangeError
- ReferenceError
- SyntaxError
- TypeError
- URIError
- AggregateError
Numbers & dates
- Number
- BigInt
- Math
- Date
Text processing
- String
- RegExp
Indexed Collections
- Array
- Int8Array
- Uint8Array
- Uint8ClampedArray
- Int16Array
- Uint16Array
- Int32Array
- Uint32Array
- BigInt64Array
- BigUint64Array
- Float32Array
- Float64Array
Keyed collections
- Map
- Set
- WeakMap
- WeakSet
Structured data
- ArrayBuffer
- SharedArrayBuffer
- DataView
- Atomics
- JSON
Memory management
- WeakRef
- FinalizationRegistry
Control abstraction
- Promise
- GeneratorFunction
- AsyncGeneratorFunction
- Generator
- AsyncGenerator
- AsyncFunction
Reflection
- Reflect
- Proxy
Internationalization
- Intl
- Intl.Collator
- Intl.DateTimeFormat
- Intl.DisplayNames
- Intl.ListFormat
- Intl.Locale
- Intl.NumberFormat
- Intl.PluralRules
- Intl.RelativeTimeFormat
- Intl.Segmenter
Statements
JavaScript statements and declarations
Control flow
- Block
- Empty statement
- break
- continue
- if...else
- switch
- throw
- try...catch
Declarations
- var
- let
- const
Functions and classes
- function
- function*
- async function
- async function*
- return
- class
Iterations
- do...while
- for
- for...in
- for...of
- for await...of
- while
Other
- debugger
- export
- import
- label
- with
Expressions and operators
JavaScript expressions and operators.
Primary expressions
- this
- function
- class
- function*
- yield
- yield*
- async function
- async function*
- await
- []
- {}
- /ab+c/i
- ( )
- null
Left-hand-side expressions
- Property accessors
- ?. (Optional chaining)
- new
- new.target
- import.meta
- super
- ...obj
Increment & decrement
- A++
- A--
- ++A
- --A
Unary operators
- delete
- void
- typeof
- +
- -
- ~
- !
Arithmetic operators
- +
- -
- /
- *
- %
- **
Relational operators
- in
- instanceof
- <
- >
- <=
- >=
Equality operators
- ==
- !=
- ===
- !==
Bitwise shift operators
- <<
- >>
- >>>
Binary bitwise operators
- &
- |
- ^
Binary logical operators
- &&
- ||
- ??
Conditional (ternary) operator
- (condition ? ifTrue : ifFalse)
Assignment operators
- =
- *=
- **=
- /=
- %=
- +=
- -=
- <<=
- >>=
- >>>=
- &=
- ^=
- |=
- &&=
- ||=
- ??=
- [a, b] = arr
- { a, b } = obj
Comma operators
- ,
Functions
JavaScript functions.
- Arrow Functions
- Default parameters
- Rest parameters
- arguments
- Method definitions
- getter
- setter
Classes
JavaScript classes.
Additional reference pages
- Lexical grammar
- Data types and data structures
- Strict mode
- Deprecated features