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Diffstat (limited to 'files/fr/web/javascript/reference/global_objects/array/flatmap/index.html')
-rw-r--r-- | files/fr/web/javascript/reference/global_objects/array/flatmap/index.html | 25 |
1 files changed, 10 insertions, 15 deletions
diff --git a/files/fr/web/javascript/reference/global_objects/array/flatmap/index.html b/files/fr/web/javascript/reference/global_objects/array/flatmap/index.html index d0049d6c3c..4117829f18 100644 --- a/files/fr/web/javascript/reference/global_objects/array/flatmap/index.html +++ b/files/fr/web/javascript/reference/global_objects/array/flatmap/index.html @@ -14,10 +14,6 @@ original_slug: Web/JavaScript/Reference/Objets_globaux/Array/flatMap <p>La méthode <code><strong>flatMap()</strong></code> permet d'appliquer une fonction à chaque élément du tableau puis d'aplatir le résultat en un tableau. Cela correspond à l'enchaînement de {{jsxref("Array.prototype.map()")}} suivi de {{jsxref("Array.prototype.flat()")}} de profondeur 1. <code>flatMap</code> est plus efficace que la combinaison de ces deux opérations, souvent réalisées conjointement.</p> -<p class="hidden">\{{EmbedInteractiveExample("pages/js/array-flatmap.html")}}</p> - -<p class="hidden">Le code source de cet exemple interactif est disponible dans un dépôt GitHub. Si vous souhaitez contribuez à ces exemples, n'hésitez pas à cloner <a href="https://github.com/mdn/interactive-examples">https://github.com/mdn/interactive-examples</a> et à envoyer une <em>pull request</em> !</p> - <h2 id="Syntaxe">Syntaxe</h2> <pre class="syntaxbox"><var>var new_array = arr</var>.flatMap(function <var>callback(currentValue[, index[, array]]) { @@ -30,7 +26,6 @@ original_slug: Web/JavaScript/Reference/Objets_globaux/Array/flatMap <dt><code>callback</code></dt> <dd>La fonction qui produit un élément du nouveau tableau et qui prend trois arguments : <dl> - <dt></dt> <dt><code>currentValue</code></dt> <dd>La valeur du tableau qui est traitée.</dd> <dt><code>index</code>{{optional_inline}}</dt> @@ -55,13 +50,13 @@ original_slug: Web/JavaScript/Reference/Objets_globaux/Array/flatMap <h3 id="map_et_flatMap"><code>map()</code> et <code>flatMap()</code></h3> -<pre class="brush: js">var arr1 = <span class="js source"><span class="function-call js meta"><span class="js meta"><span class="brace js meta square"><span>[</span></span><span class="constant decimal js numeric"><span>1</span></span><span class="comma delimiter js meta object"><span>,</span></span><span> </span><span class="brace js meta square"><span>2, 3, 4]; +<pre class="brush: js">var arr1 = [1, 2, 3, 4]; -arr1.map(</span></span></span></span></span>x => [x * 2]<span class="js source"><span class="function-call js meta"><span class="js meta"><span class="brace js meta square"><span>);</span></span></span></span></span> +arr1.map(x => [x * 2]); // [[2], [4], [6], [8]] -arr1.flatMap(x => [x * 2]<span class="js source"><span class="function-call js meta"><span class="js meta"><span class="brace js meta square"><span>); -// [2, 4, 6, 8]</span></span></span></span></span> +arr1.flatMap(x => [x * 2]); +// [2, 4, 6, 8] // seul un niveau est aplati arr1.flatMap(x => [[x * 2]]); @@ -81,18 +76,18 @@ tableau1.flatMap(x => x.split(" ")); <p>On notera que la longueur de la liste obtenue avec <code>flatMap</code> est différente de la longueur de la liste originale.</p> -<div class="line"><span class="js source"><span class="comment double-slash js line"><span class="comment definition js punctuation"><span>//</span></span><span>=> [1, 2, 3, 4, 5, 6, 7, 8, 9]</span></span></span></div> +<pre>//=> [1, 2, 3, 4, 5, 6, 7, 8, 9]</pre> <h2 id="Équivalent">Équivalent</h2> <h3 id="reduce_et_concat"><code>reduce()</code> et <code>concat()</code></h3> -<pre class="brush: js line-numbers language-js"><code class="language-js"><span class="keyword token">var</span> arr <span class="operator token">=</span> <span class="punctuation token">[</span><span class="number token">1</span><span class="punctuation token">,</span> <span class="number token">2</span><span class="punctuation token">,</span> <span class="number token">3</span><span class="punctuation token">,</span> <span class="number token">4</span><span class="punctuation token">]</span><span class="punctuation token">;</span> +<pre class="brush: js">var arr = [1, 2, 3, 4]; -arr<span class="punctuation token">.</span><span class="function token">flatMap</span><span class="punctuation token">(</span>x <span class="operator token">=</span><span class="operator token">></span> <span class="punctuation token">[x, </span>x <span class="operator token">*</span> <span class="number token">2</span><span class="punctuation token">]</span><span class="punctuation token">)</span><span class="punctuation token">;</span> -<span class="comment token">// est équivalent à</span> -arr<span class="punctuation token">.</span><span class="function token">reduce</span><span class="punctuation token">(</span><span class="punctuation token">(</span>acc<span class="punctuation token">,</span> x<span class="punctuation token">)</span> <span class="operator token">=</span><span class="operator token">></span> acc<span class="punctuation token">.</span><span class="function token">concat</span><span class="punctuation token">(</span><span class="punctuation token">[x, </span>x <span class="operator token">*</span> <span class="number token">2</span><span class="punctuation token">]</span><span class="punctuation token">)</span><span class="punctuation token">,</span> <span class="punctuation token">[</span><span class="punctuation token">]</span><span class="punctuation token">)</span><span class="punctuation token">;</span> -<span class="comment token">// [1, 2, 2, 4, 3, 6, 4, 8]</span></code></pre> +arr.flatMap(x => [x, x * 2]); +// est équivalent à +arr.reduce((acc, x) => acc.concat([x, x * 2]), []); +// [1, 2, 2, 4, 3, 6, 4, 8]</pre> <h2 id="Spécifications">Spécifications</h2> |