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JavaScript | MDN

 Généré le 22 Janvier 2026 11:25

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Le score est de 49/100

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Titre

JavaScript | MDN

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Description

JavaScript (JS) is a lightweight interpreted (or just-in-time compiled) programming language with first-class functions. While it is most well-known as the scripting language for Web pages, many non-browser environments also use it, such as Node.js, Apache CouchDB and Adobe Acrobat. JavaScript is a prototype-based, garbage-collected, dynamic language, supporting multiple paradigms such as imperative, functional, and object-oriented.

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Niveaux de titre

H1 H2 H3 H4 H5 H6
1 5 3 0 0 0
  • [H1] JavaScript
  • [H2] In this article
  • [H2] Beginner's tutorials
  • [H2] JavaScript guides
  • [H2] Reference
  • [H2] Help improve MDN
  • [H3] Fundamental language guides
  • [H3] Intermediate
  • [H3] Advanced

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Nous avons trouvé un total de 450 lien(s) dont 12 lien(s) vers des fichiers

Texte d'ancre Type Juice
Skip to main content Interne Passing Juice
Skip to search Interne Passing Juice
just-in-time compiled Interne Passing Juice
first-class functions Interne Passing Juice
many non-browser environments Externe Passing Juice
Node.js Interne Passing Juice
Apache CouchDB Externe Passing Juice
Adobe Acrobat Externe Passing Juice
prototype-based Interne Passing Juice
garbage-collected Interne Passing Juice
dynamic Interne Passing Juice
APIs Interne Passing Juice
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ECMAScript Language Specification Externe Passing Juice
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stages Externe Passing Juice
Java programming language Externe Passing Juice
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JavaScript reference Interne Passing Juice
Beginner's tutorials Interne Passing Juice
JavaScript guides Interne Passing Juice
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learn web development core modules Interne Passing Juice
Your first website: Adding interactivity Interne Passing Juice
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MDN contributors Interne Passing Juice
JavaScript Interne Passing Juice
Introduction Interne Passing Juice
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Control flow and error handling Interne Passing Juice
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Functions Interne Passing Juice
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Character escape: \n, \u{...} Interne Passing Juice
Disjunction: | Interne Passing Juice
Input boundary assertion: ^, $ Interne Passing Juice
Literal character: a, b Interne Passing Juice
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Unicode character class escape: \p{...}, \P{...} Interne Passing Juice
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AggregateError: No Promise in Promise.any was resolved Interne Passing Juice
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InternalError: too much recursion Interne Passing Juice
RangeError: argument is not a valid code point Interne Passing Juice
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RangeError: form must be one of 'NFC', 'NFD', 'NFKC', or 'NFKD' Interne Passing Juice
RangeError: invalid array length Interne Passing Juice
RangeError: invalid date Interne Passing Juice
RangeError: precision is out of range Interne Passing Juice
RangeError: radix must be an integer Interne Passing Juice
RangeError: repeat count must be less than infinity Interne Passing Juice
RangeError: repeat count must be non-negative Interne Passing Juice
RangeError: x can't be converted to BigInt because it isn't an integer Interne Passing Juice
ReferenceError: "x" is not defined Interne Passing Juice
ReferenceError: assignment to undeclared variable "x" Interne Passing Juice
ReferenceError: can't access lexical declaration 'X' before initialization Interne Passing Juice
ReferenceError: must call super constructor before using 'this' in derived class constructor Interne Passing Juice
ReferenceError: super() called twice in derived class constructor Interne Passing Juice
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SyntaxError: raw bracket is not allowed in regular expression with unicode flag Interne Passing Juice
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TypeError: BigInt value can't be serialized in JSON Interne Passing Juice
TypeError: calling a builtin X constructor without new is forbidden Interne Passing Juice
TypeError: can't access/set private field or method: object is not the right class Interne Passing Juice
TypeError: can't assign to property "x" on "y": not an object Interne Passing Juice
TypeError: can't convert BigInt to number Interne Passing Juice
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TypeError: can't define property "x": "obj" is not extensible Interne Passing Juice
TypeError: can't delete non-configurable array element Interne Passing Juice
TypeError: can't redefine non-configurable property "x" Interne Passing Juice
TypeError: can't set prototype of this object Interne Passing Juice
TypeError: can't set prototype: it would cause a prototype chain cycle Interne Passing Juice
TypeError: cannot use 'in' operator to search for 'x' in 'y' Interne Passing Juice
TypeError: class constructors must be invoked with 'new' Interne Passing Juice
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TypeError: invalid Array.prototype.sort argument Interne Passing Juice
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TypeError: Reduce of empty array with no initial value Interne Passing Juice
TypeError: setting getter-only property "x" Interne Passing Juice
TypeError: WeakSet key/WeakMap value 'x' must be an object or an unregistered symbol Interne Passing Juice
TypeError: X.prototype.y called on incompatible type Interne Passing Juice
URIError: malformed URI sequence Interne Passing Juice
Warning: -file- is being assigned a //# sourceMappingURL, but already has one Interne Passing Juice
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Blog Interne Passing Juice
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Advertise with us Interne Passing Juice
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Mots-clefs

Nuage de mots-clefs

regular syntaxerror assignment typeerror class object function invalid javascript expression

Cohérence des mots-clefs

Mot-clef Contenu Titre Mots-clefs Description Niveaux de titre
syntaxerror 73
javascript 44
typeerror 38
expression 22
class 19

Ergonomie

Url

Domaine : mdn.io

Longueur : 6

Favicon

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Imprimabilité

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Langue

Bien. Votre langue est : en.

Dublin Core

Cette page ne profite pas des métadonnées Dublin Core.

Document

Doctype

HTML 5

Encodage

Parfait. Votre charset est UTF-8.

Validité W3C

Erreurs : 0

Avertissements : 0

E-mail confidentialité

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HTML obsolètes

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Astuces vitesse

Excellent, votre site n'utilise pas de tableaux imbriqués.
Mauvais, votre site web utilise des styles css inline.
Mauvais, votre site web contient trop de fichiers CSS (plus de 4).
Parfait, votre site web contient peu de fichiers javascript.
Dommage, votre site n'est pas optimisé avec gzip.

Mobile

Optimisation mobile

Icône Apple
Méta tags viewport
Contenu FLASH

Optimisation

Sitemap XML

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Robots.txt

https://mdn.io/robots.txt

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Mesures d'audience

Manquant

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