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diff --git a/files/it/web/javascript/reference/global_objects/array/includes/index.html b/files/it/web/javascript/reference/global_objects/array/includes/index.html new file mode 100644 index 0000000000..04dc817974 --- /dev/null +++ b/files/it/web/javascript/reference/global_objects/array/includes/index.html @@ -0,0 +1,162 @@ +--- +title: Array.prototype.includes() +slug: Web/JavaScript/Reference/Global_Objects/Array/includes +translation_of: Web/JavaScript/Reference/Global_Objects/Array/includes +--- +<div>{{JSRef}}</div> + +<p>Il metodo <code><strong>includes()</strong></code> determina se un array include un certo elemento, ritornando <code>true</code> o <code>false</code> a seconda del caso</p> + +<h2 id="Sintassi">Sintassi</h2> + +<pre class="syntaxbox">var <var>boolean</var> = <var>array</var>.includes(<var>searchElement</var>[, <var>fromIndex</var>])</pre> + +<h3 id="Parametri">Parametri</h3> + +<dl> + <dt><code>searchElement</code></dt> + <dd>L'elemento da cercare.</dd> + <dt><code>fromIndex</code></dt> + <dd>Opzionale. La posizione nell'array da cui partire per cercare l'elemento <code>searchElement</code>. Un valore negativo ricerca dal valore di <code>array.length + fromIndex</code> in maniera ascendente. Il valore di default è 0.</dd> +</dl> + +<h3 id="Valore_di_ritorno">Valore di ritorno</h3> + +<p>Un {{jsxref("Boolean")}}.</p> + +<h2 id="Examples">Examples</h2> + +<pre class="brush: js">[1, 2, 3].includes(2); // true +[1, 2, 3].includes(4); // false +[1, 2, 3].includes(3, 3); // false +[1, 2, 3].includes(3, -1); // true +[1, 2, NaN].includes(NaN); // true +</pre> + +<h2 id="Polyfill">Polyfill</h2> + +<pre class="brush: js">if (!Array.prototype.includes) { + Array.prototype.includes = function(searchElement /*, fromIndex*/) { + 'use strict'; + if (this == null) { + throw new TypeError('Array.prototype.includes called on null or undefined'); + } + + var O = Object(this); + var len = parseInt(O.length, 10) || 0; + if (len === 0) { + return false; + } + var n = parseInt(arguments[1], 10) || 0; + var k; + if (n >= 0) { + k = n; + } else { + k = len + n; + if (k < 0) {k = 0;} + } + var currentElement; + while (k < len) { + currentElement = O[k]; + if (searchElement === currentElement || + (searchElement !== searchElement && currentElement !== currentElement)) { // NaN !== NaN + return true; + } + k++; + } + return false; + }; +} +</pre> + +<h2 id="Specifications">Specifications</h2> + +<table class="standard-table"> + <tbody> + <tr> + <th scope="col">Specification</th> + <th scope="col">Status</th> + <th scope="col">Comment</th> + </tr> + <tr> + <td>{{SpecName('ES7', '#sec-array.prototype.includes', 'Array.prototype.includes')}}</td> + <td>{{Spec2('ES7')}}</td> + <td>Definizione iniziale.</td> + </tr> + <tr> + <td>{{SpecName('ESDraft', '#sec-array.prototype.includes', 'Array.prototype.includes')}}</td> + <td>{{Spec2('ESDraft')}}</td> + <td> </td> + </tr> + </tbody> +</table> + +<h2 id="Browser_compatibility">Browser compatibility</h2> + +<div>{{CompatibilityTable}}</div> + +<div id="compat-desktop"> +<table class="compat-table"> + <tbody> + <tr> + <th>Feature</th> + <th>Chrome</th> + <th>Firefox (Gecko)</th> + <th>Internet Explorer</th> + <th>Edge</th> + <th>Opera</th> + <th>Safari</th> + </tr> + <tr> + <td>Basic support</td> + <td> + <p>{{CompatChrome(47)}}</p> + </td> + <td>43</td> + <td>{{CompatNo}}</td> + <td>14279+</td> + <td>34</td> + <td>9</td> + </tr> + </tbody> +</table> +</div> + +<div id="compat-mobile"> +<table class="compat-table"> + <tbody> + <tr> + <th>Feature</th> + <th>Android</th> + <th>Android Webview</th> + <th>Firefox Mobile (Gecko)</th> + <th>IE Mobile</th> + <th>Opera Mobile</th> + <th>Safari Mobile</th> + <th>Chrome for Android</th> + </tr> + <tr> + <td>Basic support</td> + <td>{{CompatNo}}</td> + <td> + <p>{{CompatChrome(47)}}</p> + </td> + <td>43</td> + <td>{{CompatNo}}</td> + <td>34</td> + <td>9</td> + <td> + <p>{{CompatChrome(47)}}</p> + </td> + </tr> + </tbody> +</table> +</div> + +<h2 id="Vedi_anche">Vedi anche</h2> + +<ul> + <li>{{jsxref("TypedArray.prototype.includes()")}}</li> + <li>{{jsxref("String.prototype.includes()")}}</li> + <li>{{jsxref("Array.prototype.indexOf()")}}</li> +</ul> |