Declarations and assignments

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Syntax

var foo [= value [, foo2 [, foo3 … [, fooN]]]];
let bar [= value [, bar2 [, foo3 … [, barN]]]];
const baz = value [, baz2 = value2 [, … [, bazN = valueN]]];

Remarks

See also:

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Declarations and assignments:

*Syntax

*Remarks

*Declaration

*Assignment

*Declaring and initializing constants

*Modifying constants

*Reassigning constants

*Undefined

*Mathematic operations and assignment

Table Of Contents

0Getting started

1Comments

2Basic data types

3Built-in constants

4Variables

5Declarations and assignments

6Reserved keywords

7Data types in JavaScript

8Strings

9Escape sequences

10Template Literals

11Arrays

12Objects

13Prototypes objects

14Classes

15Variable coercion / conversion

16Map

17Set

18Arithmetic Math

19Bitwise operators

20Bitwise operators

21Unary Operators

22Comparison operations

23Conditions

24Loops

25Functions

26Arrow functions

27Date

28Date comparison

29Scope

30AJAX

31Promises

32Regular Expression

33Error Handling

34Geolocation

35Cookies

36Intervals and timeouts

37Generators

38History of visited urls

39Strict mode

40Custom Elements

41JSON

42Binary Data

43Web Storage

44Fetch

45Modules

46Screen

47Inheritance

48Timestamps

49Destructuring assignment

50Web Worker

51Debugging

52Notifications API

53WebSockets

54Web Cryptography API

55Async functions, async / await

56Constructor functions

57execCommand and contenteditable

58Performance Tips

59Design patterns

60requestAnimationFrame

61Method chaining

62Global error handling in browsers

63File API, blobs and FileReaders

64Console

65Tail call optimization

66Detecting browser

67Enumerations

68Symbols

69Localization

70Selection API

71Callbacks

72Functional JavaScript

73Modals

74Data attributes

75Event Loop

76Events

77Data manipulation

78BOM Browser Object Model

79Unit Testing

80Linters for ensuring code quality

81Automatic Semicolon Insertion

82IndexedDB

83Anti-patterns

84Navigator Object

85Modularization techniques

86Proxy

87Same origin policy, cross-origin communication

88postMessage and MessageEvent

89WeakMap

90WeakSet

91Behaviroal Design Patterns

92Server-sent events

93Async iterators

94Namespacing

95Evaluating JavaScript

96Memory efficiency

97How to make iterator usable inside async callback function

98Context this

99Setters and getters

100Vibration API

101Fluent API

102Tilde

103Security issues

104Get and set CSS custom variables

105Contributors