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Affectation aprs exponentiation (**=) - JavaScript | MDN
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Affectation aprs exponentiation (**=)

Baseline Large disponibilit

Cette fonctionnalit est bien tablie et fonctionne sur de nombreux appareils et versions de navigateurs. Elle est disponible sur tous les navigateurs depuis mars 2017.

L'oprateur d'exponentiation et d'affectation (**=) lve la valeur de la variable fournie par son oprande gauche la puissance indique par son oprande droit puis affecte le rsultat la variable reprsente par l'oprande gauche.

Dans cet article

Exemple interactif

let a = 3;

console.log((a **= 2));
// Expected output: 9

console.log((a **= 0));
// Expected output: 1

console.log((a **= "hello"));
// Expected output: NaN

Syntaxe

js
Oprateur: x **= y;
Signification: x = x ** y;

Exemples

Utiliser l'oprateur d'exponentiation et d'affectation

js
let truc = 5;
truc **= 2; // 25
truc **= "toto"; // NaN

Spcifications

Spcification
ECMAScript 2027 LanguageSpecification
# sec-assignment-operators

Compatibilit des navigateurs

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  1. JavaScript
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  3. Guide JavaScript
    1. Introduction
    2. Types et grammaire
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    6. Expressions et oprateurs
    7. Nombres et chanes de caractres
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  4. Intermdiaire
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  5. Avanc
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    3. Gestion de la mmoire
  6. Rfrences
  7. Objets natifs
    1. AggregateError
    2. Array
    3. ArrayBuffer
    4. AsyncDisposableStack
    5. AsyncFunction
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    7. AsyncGeneratorFunction
    8. AsyncIterator
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    69. undefined
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  8. Expressions et oprateurs
    1. Addition (+)
    2. Affectation aprs addition (+=)
    3. Assignement (=)
    4. Expression async function
    5. Expression async function*
    6. await
    7. ET binaire (&)
    8. Affectation aprs ET binaire (&=)
    9. NON binaire (~)
    10. OU binaire (|)
    11. Affectation aprs OU binaire (|=)
    12. OU exclusif binaire (^)
    13. Affectation aprs OU exclusif binaire (^=)
    14. class
    15. L'oprateur virgule
    16. L'oprateur conditionnel
    17. Dcrmentation (--)
    18. L'oprateur delete
    19. Affecter par dcomposition
    20. Division (/)
    21. Affectation aprs division (/=)
    22. galit (==)
    23. Exponentiation (**)
    24. Affectation aprs exponentiation (**=)
    25. L'oprateur function
    26. Expression function*
    27. Suprieur strict (>)
    28. Suprieur ou gal (>=)
    29. Oprateur de groupement
    30. import.meta
      1. import.meta.resolve()
    31. import
    32. L'oprateur in
    33. Incrmentation (++)
    34. Ingalit (!=)
    35. instanceof
    36. Dcalage binaire gauche (<<)
    37. Affectation aprs dcalage gauche (<<=)
    38. Infrieur strict (<)
    39. Infrieur ou gal (<=)
    40. ET logique (&&)
    41. Affectation aprs ET logique (&&=)
    42. NON logique (!)
    43. OU logique (||)
    44. Affectation aprs OU logique (||=)
    45. Multiplication (*)
    46. Affectation aprs multiplication (*=)
    47. L'oprateur new
    48. new.target
    49. null
    50. Affectation aprs coalescence des nuls (??=)
    51. Oprateur de coalescence des nuls (Nullish coalescing operator)
    52. Initialisateur d'objet
    53. Prcdence des oprateurs
    54. Chanage optionnel (optional chaining)
    55. Accesseurs de proprits
    56. Reste (%)
    57. Affectation aprs reste (%=)
    58. Dcalage binaire droite (>>)
    59. Affectation aprs dcalage droite (>>=)
    60. Syntaxe de dcomposition
    61. galit stricte (===)
    62. Ingalit stricte (!==)
    63. Soustraction (-)
    64. Affectation aprs soustraction (-=)
    65. super
    66. L'oprateur this
    67. typeof
    68. Ngation unaire (-)
    69. Plus unaire (+)
    70. Dcalage binaire droite non-sign (>>>)
    71. Affectation aprs dcalage droite non sign (>>>=)
    72. L'oprateur void
    73. yield
    74. yield*
  9. Instructions et dclarations
    1. async function
    2. async function*
    3. await using
    4. bloc
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  12. Expressions rationnelles
    1. Backreference: \1, \2
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  13. Erreurs
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    32. SyntaxError: continue must be inside loop
    33. SyntaxError: duplicate capture group name in regular expression
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    35. SyntaxError: for-in loop head declarations may not have initializers
    36. SyntaxError: function statement requires a name
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    38. SyntaxError: getter and setter for private name #x should either be both static or non-static
    39. SyntaxError: getter functions must have no arguments
    40. SyntaxError: identifier starts immediately after numeric literal
    41. SyntaxError: illegal character
    42. SyntaxError: import declarations may only appear at top level of a module
    43. SyntaxError: incomplete quantifier in regular expression
    44. ReferenceError: invalid assignment left-hand side
    45. SyntaxError: invalid BigInt syntax
    46. SyntaxError: invalid capture group name in regular expression
    47. SyntaxError: invalid character in class in regular expression
    48. SyntaxError: invalid class set operation in regular expression
    49. SyntaxError: invalid decimal escape in regular expression
    50. SyntaxError: invalid identity escape in regular expression
    51. SyntaxError: invalid named capture reference in regular expression
    52. SyntaxError: invalid property name in regular expression
    53. SyntaxError: invalid range in character class
    54. SyntaxError: invalid regexp group
    55. SyntaxError: invalid regular expression flag "x"
    56. SyntaxError: invalid unicode escape in regular expression
    57. SyntaxError: JSON.parse: bad parsing
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    60. SyntaxError: missing ) after argument list
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    66. SyntaxError: missing formal parameter
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    77. SyntaxError: raw bracket is not allowed in regular expression with unicode flag
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    79. SyntaxError: reference to undeclared private field or method #x
    80. SyntaxError: rest parameter may not have a default
    81. SyntaxError: return not in function
    82. SyntaxError: setter functions must have one argument
    83. SyntaxError: unterminated string literal
    84. SyntaxError: super() is only valid in derived class constructors
    85. SyntaxError: tagged template cannot be used with optional chain
    86. SyntaxError: Unexpected '#' used outside of class body
    87. SyntaxError: Unexpected token
    88. SyntaxError: unlabeled break must be inside loop or switch
    89. SyntaxError: unparenthesized unary expression can't appear on the left-hand side of '**'
    90. SyntaxError: use of super property/member accesses only valid within methods or eval code within methods
    91. SyntaxError: Using //@ to indicate sourceURL pragmas is deprecated. Use //# instead
    92. ReferenceError: deprecated caller or arguments usage
    93. TypeError: 'x' is not iterable
    94. TypeError: "x" is (not) "y"
    95. TypeError: "x" is not a constructor
    96. TypeError: "x" is not a function
    97. TypeError: "x" is not a non-null object
    98. TypeError: "x" is read-only
    99. TypeError: already executing generator
    100. TypeError: BigInt value can't be serialized in JSON
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    102. TypeError: can't access/set private field or method: object is not the right class
    103. TypeError: can't assign to property "x" on "y": not an object
    104. TypeError: can't convert BigInt to number
    105. TypeError: can't convert x to BigInt
    106. TypeError: can't define property "x": "obj" is not extensible
    107. TypeError: can't delete non-configurable array element
    108. TypeError: can't redefine non-configurable property "x"
    109. TypeError: can't set prototype of this object
    110. TypeError: can't set prototype: it would cause a prototype chain cycle
    111. TypeError: invalid 'in' operand "x"
    112. TypeError: class constructors must be invoked with 'new'
    113. TypeError: cyclic object value
    114. TypeError: derived class constructor returned invalid value x
    115. TypeError: getting private setter-only property
    116. TypeError: Initializing an object twice is an error with private fields/methods
    117. TypeError: invalid 'instanceof' operand 'x'
    118. TypeError: invalid Array.prototype.sort argument
    119. TypeError: invalid assignment to const "x"
    120. TypeError: Iterator/AsyncIterator constructor can't be used directly
    121. TypeError: matchAll/replaceAll must be called with a global RegExp
    122. TypeError: More arguments needed
    123. TypeError: "x" has no properties
    124. TypeError: property "x" is non-configurable and can't be deleted
    125. TypeError: Reduce of empty array with no initial value
    126. TypeError: setting a property that has only a getter
    127. TypeError: WeakSet key/WeakMap value 'x' must be an object or an unregistered symbol
    128. TypeError: X.prototype.y called on incompatible type
    129. URIError: malformed URI sequence
    130. Warning: -file- is being assigned a //# sourceMappingURL, but already has one
    131. Warning: unreachable code after return statement
  14. Divers
    1. Aperu des technologies JavaScript
    2. Modle d'excution
    3. Grammaire lexicale
    4. Protocoles d'itration
    5. Mode strict
    6. Gabarits de chanes de caractres
    7. Virgules finales
    8. Fonctionnalits dprcies
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