{"id":68926,"date":"2023-05-10T03:00:16","date_gmt":"2023-05-10T02:00:16","guid":{"rendered":"https:\/\/kinqsta.com\/fr\/?p=68926&post_type=knowledgebase&preview_id=68926"},"modified":"2025-10-01T20:43:18","modified_gmt":"2025-10-01T19:43:18","slug":"typeerror-cannot-read-property-map-of-undefined-react","status":"publish","type":"post","link":"https:\/\/kinqsta.com\/fr\/blog\/typeerror-cannot-read-property-map-of-undefined-react\/","title":{"rendered":"Comment corriger l’erreur \u00ab TypeError : Cannot Read Property ‘Map’ of Undefined \u00bb dans React"},"content":{"rendered":"

Vous \u00eates confront\u00e9 \u00e0 l’erreur frustrante \u00ab TypeError : Cannot Read Property ‘Map’ of Undefined \u00bb dans votre application React<\/a> ? Cette erreur peut \u00eatre difficile \u00e0 d\u00e9boguer, mais n’ayez crainte, nous avons tout ce qu’il vous faut.<\/p>\n

Dans cet article, nous allons vous pr\u00e9senter les causes communes et les solutions pour vous aider \u00e0 r\u00e9soudre cette erreur. Que vous soyez un d\u00e9veloppeur<\/a> React chevronn\u00e9 ou que vous d\u00e9butiez, ce guide vous aidera \u00e0 remettre votre application sur les rails.
\n

<\/div><\/kinsta-auto-toc><\/p>\n

Quelles sont les causes de l’erreur \u00ab TypeError : Cannot Read Property ‘Map’ of Undefined \u00bb ?<\/h2>\n

L’erreur \u00ab TypeError : Cannot Read Property ‘Map’ of Undefined \u00bb se produit g\u00e9n\u00e9ralement lorsque vous essayez d’acc\u00e9der \u00e0 une propri\u00e9t\u00e9 ou \u00e0 une m\u00e9thode d’une valeur ind\u00e9finie dans votre code React.<\/p>\n

En termes clairs, l’erreur se produit lorsque vous essayez de mapper une valeur non d\u00e9finie, comme un tableau qui n’a pas \u00e9t\u00e9 initialis\u00e9 ou qui n’a pas encore re\u00e7u de donn\u00e9es.<\/p>\n

Dans l’exemple ci-dessous, vous obtenez des \u00e9l\u00e9ments de t\u00e2ches \u00e0 partir de donn\u00e9es JSON Placeholder<\/a>, mais la m\u00e9thode map est appel\u00e9e avant que les donn\u00e9es provenant d’une requ\u00eate API<\/a> ne soient arriv\u00e9es.<\/p>\n

import { useState, useEffect } from 'react';\n\nfunction App() {\n  const [todos, setTodos] = useState();\n\n  useEffect(() => {\n    const getTodos = async () => {\n      const response = await fetch(\n        'https:\/\/jsonplaceholder.typicode.com\/todos?_limit=5'\n      );\n      const data = await response.json();\n      setTodos(data);\n    };\n    getTodos();\n  }, []);\n\n  console.log(todos);\n\n  return (\n    <div>\n      {todos.map((todo) => (\n        <div key={todo.id}>\n          <h2>Item: {todo.title}<\/h2>\n        <\/div>\n      ))}\n    <\/div>\n  );\n}\n\nexport default App;<\/code><\/pre>\n
Le code ci-dessus g\u00e9n\u00e8re l’erreur \u00ab TypeError : Cannot read properties of undefined (reading ‘map’) \u00bb :<\/p>\n
\"Message
Message d’erreur TypeError : Cannot read properties of undefined (reading ‘map’)<\/figcaption><\/figure>\n
Vous devez chercher un moyen de faire savoir \u00e0 React<\/a> que l’\u00e9tat todos est un tableau avant m\u00eame que le tableau ne soit rempli, ou vous devez \u00e9viter que la m\u00e9thode map ne s’ex\u00e9cute jusqu’\u00e0 ce que la variable \u00e9tat todos re\u00e7oive ses donn\u00e9es de la requ\u00eate API.<\/p>\n\n
3 fa\u00e7ons de corriger l’erreur \u00ab TypeError : Cannot Read Property ‘Map’ of Undefined \u00bb<\/h2>\n
Voici trois fa\u00e7ons de corriger l’erreur \u00ab TypeError : Cannot Read Property ‘Map’ of Undefined \u00bb dans React :<\/p>\n
    \n
  1. Initialisez votre variable d’\u00e9tat \u00e0 un tableau vide<\/li>\n
  2. Utilisez des op\u00e9rateurs de comparaison<\/li>\n
  3. Utilisez l’op\u00e9rateur de cha\u00eenage optionnel ( ?.)<\/li>\n<\/ol>\n
    Explorons chacune de ces solutions et comment elles peuvent vous aider \u00e0 r\u00e9soudre l’erreur dans votre code React.<\/p>\n
    1. Initialiser votre variable d’\u00e9tat \u00e0 un tableau vide<\/h3>\n
    L’une des solutions directes \u00e0 l’erreur \u00ab TypeError : Cannot Read Property ‘Map’ of Undefined \u00bb est de s’assurer que la variable tableau que vous essayez de mapper est d\u00e9finie.<\/p>\n
    Vous pouvez initialiser votre variable d’\u00e9tat \u00e0 un tableau vide par d\u00e9faut, ce qui garantira que la variable existe toujours et qu’elle ne produira pas d’erreur lorsque vous tenterez de l’affecter \u00e0 un tableau.<\/p>\n
    Par exemple, voici deux composants similaires, la variable d’\u00e9tat du premier n’est pas initialis\u00e9e \u00e0 un tableau vide, alors que celle du second l’est :<\/p>\n
    \/\/ Before initializing your state variable to an empty array\nfunction MyComponent() {\n  const [myList, setMyList] = useState();\n  \n  return (\n    <ul>\n      {myList.map(item => <li>{item}<\/li>)}\n    <\/ul>\n  );\n}\n\n\/\/ After initializing your state variable to an empty array\nfunction MyComponent() {\n  const [myList, setMyList] = useState([]);\n\n  return (\n    <ul>\n      {myList.map(item => <li>{item}<\/li>)}\n    <\/ul>\n  );\n}<\/code><\/pre>\n
    Dans l’exemple ci-dessus, la variable d’\u00e9tat myList<\/code> est initialis\u00e9e \u00e0 un tableau vide par d\u00e9faut en utilisant useState([])<\/code>. Cela garantit que m\u00eame si myList<\/code> est ind\u00e9fini au d\u00e9part, il s’agira toujours d’un tableau et qu’il n’y aura pas d’erreur de type \u00ab TypeError : Cannot Read Property ‘Map’ of Undefined \u00bb.<\/p>\n
    Pour l’exemple de la r\u00e9cup\u00e9ration, vous pouvez \u00e9galement initialiser la variable d’\u00e9tat todos<\/code> \u00e0 un tableau vide ([]<\/code>) :<\/p>\n
    import { useState, useEffect } from 'react';\n\nfunction App() {\n  \/\/ Initialize the state to an empty array of todos.\n  const [todos, setTodos] = useState([]);\n\n  useEffect(() => {\n    const getTodos = async () => {\n      const response = await fetch(\n        'https:\/\/jsonplaceholder.typicode.com\/todos?_limit=5'\n      );\n      const data = await response.json();\n      setTodos(data);\n    };\n    getTodos();\n  }, []);\n\n  console.log(todos);\n\n  return (\n    <div>\n      {todos.map((todo) => (\n        <div key={todo.id}>\n          <h2>Item: {todo.title}<\/h2>\n       <\/div>\n      ))}\n    <\/div>\n  );\n}\n\nexport default App;<\/code><\/pre>\n
    2. Utiliser des op\u00e9rateurs de comparaison<\/h3>\n
    Une autre solution consiste \u00e0 utiliser des op\u00e9rateurs de comparaison pour v\u00e9rifier si la variable de tableau est d\u00e9finie avant de la recouvrir. Pour cela, vous pouvez utiliser l’op\u00e9rateur ternaire ou l’op\u00e9rateur logique AND (&&).<\/p>\n
    Voici des exemples d’utilisation de l’op\u00e9rateur ternaire <\/em>:<\/p>\n
    function MyComponent() {\n  const [myList, setMyList] = useState();\n\n  return (\n    <ul>\n      {myList ? myList.map(item => <li>{item}<\/li>) : null}\n    <\/ul>\n  );\n}<\/code><\/pre>\n
    Dans cet exemple, vous v\u00e9rifiez si la variable de tableau myList<\/code> est d\u00e9finie avant d’essayer de la mapper. Si myList<\/code> n’est pas d\u00e9fini, l’op\u00e9rateur ternaire renvoie null et rien n’est rendu. Si myList<\/code> est d\u00e9fini, la fonction map est appel\u00e9e et les \u00e9l\u00e9ments de la liste sont rendus.<\/p>\n
    Cette m\u00e9thode est similaire \u00e0 l’utilisation de l’op\u00e9rateur logique AND :<\/p>\n
    function MyComponent() {\n  const [myList, setMyList] = useState();\n\n  return (\n    <ul>\n      {myList && myList.map(item => <li>{item}<\/li>)}\n    <\/ul>\n  );\n}<\/code><\/pre>\n
    En utilisant des op\u00e9rateurs de comparaison tels que l’op\u00e9rateur ternaire, vous pouvez g\u00e9rer le chargement, de sorte que quelque chose d’autre s’affiche \u00e0 l’\u00e9cran pendant que vous recherchez des donn\u00e9es dans l’API :<\/p>\n
    import { useState, useEffect } from 'react';\n\nfunction App() {\n  const [todos, setTodos] = useState();\n\n  useEffect(() => {\n    const getTodos = async () => {\n      const response = await fetch(\n        'https:\/\/jsonplaceholder.typicode.com\/todos?_limit=5'\n      );\n      const data = await response.json();\n      setTodos(data);\n    };\n    getTodos();\n  }, []);\n\n  console.log(todos);\n\n  return (\n   <div>\n      {todos ? (\n        todos.map((todo) => (\n          <div key={todo.id}>\n            <h2>Item: {todo.title}<\/h2>\n          <\/div>\n        ))\n      ) : (\n        <h1>Loading...<\/h1>\n      )}\n    <\/div>\n  );\n}\n\nexport default App;<\/code><\/pre>\n
    3. Utiliser l’op\u00e9rateur de cha\u00eenage optionnel ( ?.)<\/h3>\n
    Vous pouvez \u00e9galement utiliser l’op\u00e9rateur de cha\u00eenage optionnel ( ?.) introduit dans ES2020. Cet op\u00e9rateur vous permet d’acc\u00e9der en toute s\u00e9curit\u00e9 \u00e0 des propri\u00e9t\u00e9s ou \u00e0 des m\u00e9thodes, telles que la m\u00e9thode map d’un tableau, sans g\u00e9n\u00e9rer d’erreur si le tableau est ind\u00e9fini.<\/p>\n
    Voici un exemple de composant fonctionnel qui utilise l’op\u00e9rateur de cha\u00eenage pour v\u00e9rifier la variable d’\u00e9tat myList<\/code>:<\/p>\n
    function MyComponent() {\n  const [myList, setMyList] = useState();\n\n  return (\n    <div>\n      {myList?.map((item) => (\n        <p>{item}<\/p>\n      ))}\n    <\/div>\n  );\n}<\/code><\/pre>\n
    Dans l’exemple ci-dessus, vous utilisez l’op\u00e9rateur de cha\u00eenage optionnel pour acc\u00e9der \u00e0 la variable de tableau myList<\/code> en toute s\u00e9curit\u00e9. Si myList<\/code> est ind\u00e9fini, rien ne sera rendu. Si myList<\/code> est d\u00e9fini, la m\u00e9thode map sera appel\u00e9e et les \u00e9l\u00e9ments de la liste seront rendus.<\/p>\n\n
    R\u00e9sum\u00e9<\/h2>\n
    L’erreur \u00ab TypeError : Cannot Read Property ‘Map’ of Undefined \u00bb peut se produire dans React lors de l’utilisation de la m\u00e9thode map sur une valeur non d\u00e9finie ou nulle.<\/p>\n
    Pour corriger cette erreur, nous avons discut\u00e9 de trois solutions. Cependant, l’utilisation d’op\u00e9rateurs de comparaison est la solution la plus polyvalente car elle permet de g\u00e9rer des situations o\u00f9 votre API peut envoyer une r\u00e9ponse vide ou une valeur nulle.<\/p>\n
    En outre, si vous n’\u00eates pas s\u00fbr que les donn\u00e9es que vous recevrez seront un tableau, vous pouvez ajouter des m\u00e9thodes pour v\u00e9rifier et convertir le type de donn\u00e9es avant d’appeler la m\u00e9thode map.<\/p>\n
    D\u00e9couvrez l’h\u00e9bergement d’applications<\/a> de Kinsta et lancez votre prochain projet React<\/a> d\u00e8s aujourd’hui !<\/p>\n
    \u00c0 vous de jouer : Avez-vous d\u00e9j\u00e0 rencontr\u00e9 ce probl\u00e8me ? Comment l’avez-vous r\u00e9solu ? Y a-t-il d’autres approches que vous avez utilis\u00e9es et qui ne sont pas abord\u00e9es dans cet article ? Faites-nous en part dans les commentaires !<\/em><\/p>\n","protected":false},"excerpt":{"rendered":"
    Vous \u00eates confront\u00e9 \u00e0 l’erreur frustrante \u00ab TypeError : Cannot Read Property ‘Map’ of Undefined \u00bb dans votre application React ? Cette erreur peut \u00eatre difficile …<\/p>\n","protected":false},"author":287,"featured_media":68927,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_kinsta_gated_content":false,"_kinsta_gated_content_redirect":"","footnotes":""},"tags":[],"topic":[1005,1004],"class_list":["post-68926","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","topic-erreurs-react","topic-react"],"yoast_head":"\nComment corriger l'erreur \u00ab TypeError : Cannot Read Property 'Map' of Undefined \u00bb dans React - Kinsta\u00ae<\/title>\n<meta name=\"description\" content=\"L'erreur frustrante \u00ab TypeError : Cannot Read Property 'Map' of Undefined \u00bb peut \u00eatre difficile \u00e0 r\u00e9soudre. Voici 3 fa\u00e7ons de r\u00e9soudre ce probl\u00e8me.\" \/>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/kinqsta.com\/fr\/blog\/typeerror-cannot-read-property-map-of-undefined-react\/\" \/>\n<meta property=\"og:locale\" content=\"fr_FR\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Comment corriger l'erreur \u00ab TypeError : Cannot Read Property 'Map' of Undefined \u00bb dans React\" \/>\n<meta property=\"og:description\" content=\"L'erreur frustrante \u00ab TypeError : Cannot Read Property 'Map' of Undefined \u00bb peut \u00eatre difficile \u00e0 r\u00e9soudre. Voici 3 fa\u00e7ons de r\u00e9soudre ce probl\u00e8me.\" \/>\n<meta property=\"og:url\" content=\"https:\/\/kinqsta.com\/fr\/blog\/typeerror-cannot-read-property-map-of-undefined-react\/\" \/>\n<meta property=\"og:site_name\" content=\"Kinsta\u00ae\" \/>\n<meta property=\"article:publisher\" content=\"https:\/\/www.facebook.com\/kinstafrance\/\" \/>\n<meta property=\"article:published_time\" content=\"2023-05-10T02:00:16+00:00\" \/>\n<meta property=\"article:modified_time\" content=\"2025-10-01T19:43:18+00:00\" \/>\n<meta property=\"og:image\" content=\"https:\/\/kinqsta.com\/fr\/wp-content\/uploads\/sites\/4\/2023\/05\/typeerror-cannot-read-property-map-of-undefined.jpg\" \/>\n\t<meta property=\"og:image:width\" content=\"6084\" \/>\n\t<meta property=\"og:image:height\" content=\"3042\" \/>\n\t<meta property=\"og:image:type\" content=\"image\/jpeg\" \/>\n<meta name=\"author\" content=\"Joel Olawanle\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:description\" content=\"L'erreur frustrante \u00ab TypeError : Cannot Read Property 'Map' of Undefined \u00bb peut \u00eatre difficile \u00e0 r\u00e9soudre. Voici 3 fa\u00e7ons de r\u00e9soudre ce probl\u00e8me.\" \/>\n<meta name=\"twitter:image\" content=\"https:\/\/kinqsta.com\/fr\/wp-content\/uploads\/sites\/4\/2023\/05\/typeerror-cannot-read-property-map-of-undefined.jpg\" \/>\n<meta name=\"twitter:creator\" content=\"@olawanle_joel\" \/>\n<meta name=\"twitter:site\" content=\"@kinsta_fr\" \/>\n<meta name=\"twitter:label1\" content=\"\u00c9crit par\" \/>\n\t<meta name=\"twitter:data1\" content=\"Joel Olawanle\" \/>\n\t<meta name=\"twitter:label2\" content=\"Dur\u00e9e de lecture estim\u00e9e\" \/>\n\t<meta name=\"twitter:data2\" content=\"7 minutes\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\/\/schema.org\",\"@graph\":[{\"@type\":\"Article\",\"@id\":\"https:\/\/kinqsta.com\/fr\/blog\/typeerror-cannot-read-property-map-of-undefined-react\/#article\",\"isPartOf\":{\"@id\":\"https:\/\/kinqsta.com\/fr\/blog\/typeerror-cannot-read-property-map-of-undefined-react\/\"},\"author\":{\"name\":\"Joel Olawanle\",\"@id\":\"https:\/\/kinqsta.com\/fr\/#\/schema\/person\/efa7de30245ca15be5ce1dcacff89c07\"},\"headline\":\"Comment corriger l’erreur \u00ab TypeError : Cannot Read Property ‘Map’ of Undefined \u00bb dans React\",\"datePublished\":\"2023-05-10T02:00:16+00:00\",\"dateModified\":\"2025-10-01T19:43:18+00:00\",\"mainEntityOfPage\":{\"@id\":\"https:\/\/kinqsta.com\/fr\/blog\/typeerror-cannot-read-property-map-of-undefined-react\/\"},\"wordCount\":1129,\"commentCount\":0,\"publisher\":{\"@id\":\"https:\/\/kinqsta.com\/fr\/#organization\"},\"image\":{\"@id\":\"https:\/\/kinqsta.com\/fr\/blog\/typeerror-cannot-read-property-map-of-undefined-react\/#primaryimage\"},\"thumbnailUrl\":\"https:\/\/kinqsta.com\/fr\/wp-content\/uploads\/sites\/4\/2023\/05\/typeerror-cannot-read-property-map-of-undefined.jpg\",\"inLanguage\":\"fr-FR\",\"potentialAction\":[{\"@type\":\"CommentAction\",\"name\":\"Comment\",\"target\":[\"https:\/\/kinqsta.com\/fr\/blog\/typeerror-cannot-read-property-map-of-undefined-react\/#respond\"]}]},{\"@type\":\"WebPage\",\"@id\":\"https:\/\/kinqsta.com\/fr\/blog\/typeerror-cannot-read-property-map-of-undefined-react\/\",\"url\":\"https:\/\/kinqsta.com\/fr\/blog\/typeerror-cannot-read-property-map-of-undefined-react\/\",\"name\":\"Comment corriger l'erreur \u00ab TypeError : Cannot Read Property 'Map' of Undefined \u00bb dans React - Kinsta\u00ae\",\"isPartOf\":{\"@id\":\"https:\/\/kinqsta.com\/fr\/#website\"},\"primaryImageOfPage\":{\"@id\":\"https:\/\/kinqsta.com\/fr\/blog\/typeerror-cannot-read-property-map-of-undefined-react\/#primaryimage\"},\"image\":{\"@id\":\"https:\/\/kinqsta.com\/fr\/blog\/typeerror-cannot-read-property-map-of-undefined-react\/#primaryimage\"},\"thumbnailUrl\":\"https:\/\/kinqsta.com\/fr\/wp-content\/uploads\/sites\/4\/2023\/05\/typeerror-cannot-read-property-map-of-undefined.jpg\",\"datePublished\":\"2023-05-10T02:00:16+00:00\",\"dateModified\":\"2025-10-01T19:43:18+00:00\",\"description\":\"L'erreur frustrante \u00ab TypeError : Cannot Read Property 'Map' of Undefined \u00bb peut \u00eatre difficile \u00e0 r\u00e9soudre. Voici 3 fa\u00e7ons de r\u00e9soudre ce probl\u00e8me.\",\"breadcrumb\":{\"@id\":\"https:\/\/kinqsta.com\/fr\/blog\/typeerror-cannot-read-property-map-of-undefined-react\/#breadcrumb\"},\"inLanguage\":\"fr-FR\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\/\/kinqsta.com\/fr\/blog\/typeerror-cannot-read-property-map-of-undefined-react\/\"]}]},{\"@type\":\"ImageObject\",\"inLanguage\":\"fr-FR\",\"@id\":\"https:\/\/kinqsta.com\/fr\/blog\/typeerror-cannot-read-property-map-of-undefined-react\/#primaryimage\",\"url\":\"https:\/\/kinqsta.com\/fr\/wp-content\/uploads\/sites\/4\/2023\/05\/typeerror-cannot-read-property-map-of-undefined.jpg\",\"contentUrl\":\"https:\/\/kinqsta.com\/fr\/wp-content\/uploads\/sites\/4\/2023\/05\/typeerror-cannot-read-property-map-of-undefined.jpg\",\"width\":6084,\"height\":3042},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\/\/kinqsta.com\/fr\/blog\/typeerror-cannot-read-property-map-of-undefined-react\/#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\/\/kinqsta.com\/fr\/\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"Erreurs React\",\"item\":\"https:\/\/kinqsta.com\/fr\/sujets\/erreurs-react\/\"},{\"@type\":\"ListItem\",\"position\":3,\"name\":\"Comment corriger l’erreur \u00ab TypeError : Cannot Read Property ‘Map’ of Undefined \u00bb dans React\"}]},{\"@type\":\"WebSite\",\"@id\":\"https:\/\/kinqsta.com\/fr\/#website\",\"url\":\"https:\/\/kinqsta.com\/fr\/\",\"name\":\"Kinsta\u00ae\",\"description\":\"Solutions d'h\u00e9bergement premium, rapides et s\u00e9curis\u00e9es\",\"publisher\":{\"@id\":\"https:\/\/kinqsta.com\/fr\/#organization\"},\"potentialAction\":[{\"@type\":\"SearchAction\",\"target\":{\"@type\":\"EntryPoint\",\"urlTemplate\":\"https:\/\/kinqsta.com\/fr\/?s={search_term_string}\"},\"query-input\":{\"@type\":\"PropertyValueSpecification\",\"valueRequired\":true,\"valueName\":\"search_term_string\"}}],\"inLanguage\":\"fr-FR\"},{\"@type\":\"Organization\",\"@id\":\"https:\/\/kinqsta.com\/fr\/#organization\",\"name\":\"Kinsta\",\"url\":\"https:\/\/kinqsta.com\/fr\/\",\"logo\":{\"@type\":\"ImageObject\",\"inLanguage\":\"fr-FR\",\"@id\":\"https:\/\/kinqsta.com\/fr\/#\/schema\/logo\/image\/\",\"url\":\"https:\/\/kinqsta.com\/fr\/wp-content\/uploads\/sites\/4\/2023\/12\/kinsta-logo.jpeg\",\"contentUrl\":\"https:\/\/kinqsta.com\/fr\/wp-content\/uploads\/sites\/4\/2023\/12\/kinsta-logo.jpeg\",\"width\":500,\"height\":500,\"caption\":\"Kinsta\"},\"image\":{\"@id\":\"https:\/\/kinqsta.com\/fr\/#\/schema\/logo\/image\/\"},\"sameAs\":[\"https:\/\/www.facebook.com\/kinstafrance\/\",\"https:\/\/x.com\/kinsta_fr\",\"https:\/\/www.instagram.com\/kinstahosting\/\",\"https:\/\/www.linkedin.com\/company\/kinsta\/\",\"https:\/\/www.pinterest.com\/kinstahosting\/\",\"https:\/\/www.youtube.com\/c\/Kinsta\"]},{\"@type\":\"Person\",\"@id\":\"https:\/\/kinqsta.com\/fr\/#\/schema\/person\/efa7de30245ca15be5ce1dcacff89c07\",\"name\":\"Joel Olawanle\",\"image\":{\"@type\":\"ImageObject\",\"inLanguage\":\"fr-FR\",\"@id\":\"https:\/\/kinqsta.com\/fr\/#\/schema\/person\/image\/\",\"url\":\"https:\/\/secure.gravatar.com\/avatar\/051bf577ce2c837846a1db9eef184758?s=96&d=mm&r=g\",\"contentUrl\":\"https:\/\/secure.gravatar.com\/avatar\/051bf577ce2c837846a1db9eef184758?s=96&d=mm&r=g\",\"caption\":\"Joel Olawanle\"},\"description\":\"Joel is a Frontend developer working at Kinsta as a Technical Editor. He is a passionate teacher with love for open source and has written over 300 technical articles majorly around JavaScript and it's frameworks.\",\"sameAs\":[\"https:\/\/joelolawanle.com\/\",\"https:\/\/www.linkedin.com\/in\/olawanlejoel\/\",\"https:\/\/x.com\/olawanle_joel\",\"https:\/\/www.youtube.com\/@joelolawanle\"],\"gender\":\"male\",\"knowsAbout\":[\"JavaScript\",\"React\",\"Next.js\"],\"knowsLanguage\":[\"English\"],\"jobTitle\":\"Technical Editor\",\"worksFor\":\"Kinsta\",\"url\":\"https:\/\/kinqsta.com\/fr\/blog\/author\/joelolawanle\/\"}]}<\/script>\n<!-- \/ Yoast SEO Premium plugin. -->","yoast_head_json":{"title":"Comment corriger l'erreur \u00ab TypeError : Cannot Read Property 'Map' of Undefined \u00bb dans React - Kinsta\u00ae","description":"L'erreur frustrante \u00ab TypeError : Cannot Read Property 'Map' of Undefined \u00bb peut \u00eatre difficile \u00e0 r\u00e9soudre. Voici 3 fa\u00e7ons de r\u00e9soudre ce probl\u00e8me.","robots":{"index":"index","follow":"follow","max-snippet":"max-snippet:-1","max-image-preview":"max-image-preview:large","max-video-preview":"max-video-preview:-1"},"canonical":"https:\/\/kinqsta.com\/fr\/blog\/typeerror-cannot-read-property-map-of-undefined-react\/","og_locale":"fr_FR","og_type":"article","og_title":"Comment corriger l'erreur \u00ab TypeError : Cannot Read Property 'Map' of Undefined \u00bb dans React","og_description":"L'erreur frustrante \u00ab TypeError : Cannot Read Property 'Map' of Undefined \u00bb peut \u00eatre difficile \u00e0 r\u00e9soudre. Voici 3 fa\u00e7ons de r\u00e9soudre ce probl\u00e8me.","og_url":"https:\/\/kinqsta.com\/fr\/blog\/typeerror-cannot-read-property-map-of-undefined-react\/","og_site_name":"Kinsta\u00ae","article_publisher":"https:\/\/www.facebook.com\/kinstafrance\/","article_published_time":"2023-05-10T02:00:16+00:00","article_modified_time":"2025-10-01T19:43:18+00:00","og_image":[{"width":6084,"height":3042,"url":"https:\/\/kinqsta.com\/fr\/wp-content\/uploads\/sites\/4\/2023\/05\/typeerror-cannot-read-property-map-of-undefined.jpg","type":"image\/jpeg"}],"author":"Joel Olawanle","twitter_card":"summary_large_image","twitter_description":"L'erreur frustrante \u00ab TypeError : Cannot Read Property 'Map' of Undefined \u00bb peut \u00eatre difficile \u00e0 r\u00e9soudre. Voici 3 fa\u00e7ons de r\u00e9soudre ce probl\u00e8me.","twitter_image":"https:\/\/kinqsta.com\/fr\/wp-content\/uploads\/sites\/4\/2023\/05\/typeerror-cannot-read-property-map-of-undefined.jpg","twitter_creator":"@olawanle_joel","twitter_site":"@kinsta_fr","twitter_misc":{"\u00c9crit par":"Joel Olawanle","Dur\u00e9e de lecture estim\u00e9e":"7 minutes"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"Article","@id":"https:\/\/kinqsta.com\/fr\/blog\/typeerror-cannot-read-property-map-of-undefined-react\/#article","isPartOf":{"@id":"https:\/\/kinqsta.com\/fr\/blog\/typeerror-cannot-read-property-map-of-undefined-react\/"},"author":{"name":"Joel Olawanle","@id":"https:\/\/kinqsta.com\/fr\/#\/schema\/person\/efa7de30245ca15be5ce1dcacff89c07"},"headline":"Comment corriger l’erreur \u00ab TypeError : Cannot Read Property ‘Map’ of Undefined \u00bb dans React","datePublished":"2023-05-10T02:00:16+00:00","dateModified":"2025-10-01T19:43:18+00:00","mainEntityOfPage":{"@id":"https:\/\/kinqsta.com\/fr\/blog\/typeerror-cannot-read-property-map-of-undefined-react\/"},"wordCount":1129,"commentCount":0,"publisher":{"@id":"https:\/\/kinqsta.com\/fr\/#organization"},"image":{"@id":"https:\/\/kinqsta.com\/fr\/blog\/typeerror-cannot-read-property-map-of-undefined-react\/#primaryimage"},"thumbnailUrl":"https:\/\/kinqsta.com\/fr\/wp-content\/uploads\/sites\/4\/2023\/05\/typeerror-cannot-read-property-map-of-undefined.jpg","inLanguage":"fr-FR","potentialAction":[{"@type":"CommentAction","name":"Comment","target":["https:\/\/kinqsta.com\/fr\/blog\/typeerror-cannot-read-property-map-of-undefined-react\/#respond"]}]},{"@type":"WebPage","@id":"https:\/\/kinqsta.com\/fr\/blog\/typeerror-cannot-read-property-map-of-undefined-react\/","url":"https:\/\/kinqsta.com\/fr\/blog\/typeerror-cannot-read-property-map-of-undefined-react\/","name":"Comment corriger l'erreur \u00ab TypeError : Cannot Read Property 'Map' of Undefined \u00bb dans React - Kinsta\u00ae","isPartOf":{"@id":"https:\/\/kinqsta.com\/fr\/#website"},"primaryImageOfPage":{"@id":"https:\/\/kinqsta.com\/fr\/blog\/typeerror-cannot-read-property-map-of-undefined-react\/#primaryimage"},"image":{"@id":"https:\/\/kinqsta.com\/fr\/blog\/typeerror-cannot-read-property-map-of-undefined-react\/#primaryimage"},"thumbnailUrl":"https:\/\/kinqsta.com\/fr\/wp-content\/uploads\/sites\/4\/2023\/05\/typeerror-cannot-read-property-map-of-undefined.jpg","datePublished":"2023-05-10T02:00:16+00:00","dateModified":"2025-10-01T19:43:18+00:00","description":"L'erreur frustrante \u00ab TypeError : Cannot Read Property 'Map' of Undefined \u00bb peut \u00eatre difficile \u00e0 r\u00e9soudre. Voici 3 fa\u00e7ons de r\u00e9soudre ce probl\u00e8me.","breadcrumb":{"@id":"https:\/\/kinqsta.com\/fr\/blog\/typeerror-cannot-read-property-map-of-undefined-react\/#breadcrumb"},"inLanguage":"fr-FR","potentialAction":[{"@type":"ReadAction","target":["https:\/\/kinqsta.com\/fr\/blog\/typeerror-cannot-read-property-map-of-undefined-react\/"]}]},{"@type":"ImageObject","inLanguage":"fr-FR","@id":"https:\/\/kinqsta.com\/fr\/blog\/typeerror-cannot-read-property-map-of-undefined-react\/#primaryimage","url":"https:\/\/kinqsta.com\/fr\/wp-content\/uploads\/sites\/4\/2023\/05\/typeerror-cannot-read-property-map-of-undefined.jpg","contentUrl":"https:\/\/kinqsta.com\/fr\/wp-content\/uploads\/sites\/4\/2023\/05\/typeerror-cannot-read-property-map-of-undefined.jpg","width":6084,"height":3042},{"@type":"BreadcrumbList","@id":"https:\/\/kinqsta.com\/fr\/blog\/typeerror-cannot-read-property-map-of-undefined-react\/#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https:\/\/kinqsta.com\/fr\/"},{"@type":"ListItem","position":2,"name":"Erreurs React","item":"https:\/\/kinqsta.com\/fr\/sujets\/erreurs-react\/"},{"@type":"ListItem","position":3,"name":"Comment corriger l’erreur \u00ab TypeError : Cannot Read Property ‘Map’ of Undefined \u00bb dans React"}]},{"@type":"WebSite","@id":"https:\/\/kinqsta.com\/fr\/#website","url":"https:\/\/kinqsta.com\/fr\/","name":"Kinsta\u00ae","description":"Solutions d'h\u00e9bergement premium, rapides et s\u00e9curis\u00e9es","publisher":{"@id":"https:\/\/kinqsta.com\/fr\/#organization"},"potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https:\/\/kinqsta.com\/fr\/?s={search_term_string}"},"query-input":{"@type":"PropertyValueSpecification","valueRequired":true,"valueName":"search_term_string"}}],"inLanguage":"fr-FR"},{"@type":"Organization","@id":"https:\/\/kinqsta.com\/fr\/#organization","name":"Kinsta","url":"https:\/\/kinqsta.com\/fr\/","logo":{"@type":"ImageObject","inLanguage":"fr-FR","@id":"https:\/\/kinqsta.com\/fr\/#\/schema\/logo\/image\/","url":"https:\/\/kinqsta.com\/fr\/wp-content\/uploads\/sites\/4\/2023\/12\/kinsta-logo.jpeg","contentUrl":"https:\/\/kinqsta.com\/fr\/wp-content\/uploads\/sites\/4\/2023\/12\/kinsta-logo.jpeg","width":500,"height":500,"caption":"Kinsta"},"image":{"@id":"https:\/\/kinqsta.com\/fr\/#\/schema\/logo\/image\/"},"sameAs":["https:\/\/www.facebook.com\/kinstafrance\/","https:\/\/x.com\/kinsta_fr","https:\/\/www.instagram.com\/kinstahosting\/","https:\/\/www.linkedin.com\/company\/kinsta\/","https:\/\/www.pinterest.com\/kinstahosting\/","https:\/\/www.youtube.com\/c\/Kinsta"]},{"@type":"Person","@id":"https:\/\/kinqsta.com\/fr\/#\/schema\/person\/efa7de30245ca15be5ce1dcacff89c07","name":"Joel Olawanle","image":{"@type":"ImageObject","inLanguage":"fr-FR","@id":"https:\/\/kinqsta.com\/fr\/#\/schema\/person\/image\/","url":"https:\/\/secure.gravatar.com\/avatar\/051bf577ce2c837846a1db9eef184758?s=96&d=mm&r=g","contentUrl":"https:\/\/secure.gravatar.com\/avatar\/051bf577ce2c837846a1db9eef184758?s=96&d=mm&r=g","caption":"Joel Olawanle"},"description":"Joel is a Frontend developer working at Kinsta as a Technical Editor. He is a passionate teacher with love for open source and has written over 300 technical articles majorly around JavaScript and it's frameworks.","sameAs":["https:\/\/joelolawanle.com\/","https:\/\/www.linkedin.com\/in\/olawanlejoel\/","https:\/\/x.com\/olawanle_joel","https:\/\/www.youtube.com\/@joelolawanle"],"gender":"male","knowsAbout":["JavaScript","React","Next.js"],"knowsLanguage":["English"],"jobTitle":"Technical Editor","worksFor":"Kinsta","url":"https:\/\/kinqsta.com\/fr\/blog\/author\/joelolawanle\/"}]}},"acf":[],"_links":{"self":[{"href":"https:\/\/kinqsta.com\/fr\/wp-json\/wp\/v2\/posts\/68926","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/kinqsta.com\/fr\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/kinqsta.com\/fr\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/kinqsta.com\/fr\/wp-json\/wp\/v2\/users\/287"}],"replies":[{"embeddable":true,"href":"https:\/\/kinqsta.com\/fr\/wp-json\/wp\/v2\/comments?post=68926"}],"version-history":[{"count":8,"href":"https:\/\/kinqsta.com\/fr\/wp-json\/wp\/v2\/posts\/68926\/revisions"}],"predecessor-version":[{"id":69016,"href":"https:\/\/kinqsta.com\/fr\/wp-json\/wp\/v2\/posts\/68926\/revisions\/69016"}],"alternate":[{"embeddable":true,"hreflang":"en","title":"English","href":"https:\/\/kinqsta.com\/fr\/wp-json\/kinsta\/v1\/posts\/68926\/translations\/en"},{"embeddable":true,"hreflang":"it","title":"Italian","href":"https:\/\/kinqsta.com\/fr\/wp-json\/kinsta\/v1\/posts\/68926\/translations\/it"},{"embeddable":true,"hreflang":"pt","title":"Portuguese","href":"https:\/\/kinqsta.com\/fr\/wp-json\/kinsta\/v1\/posts\/68926\/translations\/pt"},{"embeddable":true,"hreflang":"fr","title":"French","href":"https:\/\/kinqsta.com\/fr\/wp-json\/kinsta\/v1\/posts\/68926\/translations\/fr"},{"embeddable":true,"hreflang":"ja","title":"Japanese","href":"https:\/\/kinqsta.com\/fr\/wp-json\/kinsta\/v1\/posts\/68926\/translations\/jp"},{"embeddable":true,"hreflang":"nl","title":"Dutch","href":"https:\/\/kinqsta.com\/fr\/wp-json\/kinsta\/v1\/posts\/68926\/translations\/nl"},{"embeddable":true,"hreflang":"es","title":"Spanish","href":"https:\/\/kinqsta.com\/fr\/wp-json\/kinsta\/v1\/posts\/68926\/translations\/es"},{"embeddable":true,"hreflang":"de","title":"German","href":"https:\/\/kinqsta.com\/fr\/wp-json\/kinsta\/v1\/posts\/68926\/translations\/de"},{"href":"https:\/\/kinqsta.com\/fr\/wp-json\/kinsta\/v1\/posts\/68926\/tree"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/kinqsta.com\/fr\/wp-json\/wp\/v2\/media\/68927"}],"wp:attachment":[{"href":"https:\/\/kinqsta.com\/fr\/wp-json\/wp\/v2\/media?parent=68926"}],"wp:term":[{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/kinqsta.com\/fr\/wp-json\/wp\/v2\/tags?post=68926"},{"taxonomy":"topic","embeddable":true,"href":"https:\/\/kinqsta.com\/fr\/wp-json\/wp\/v2\/topic?post=68926"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}