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diff --git a/files/es/web/javascript/reference/global_objects/set/index.html b/files/es/web/javascript/reference/global_objects/set/index.html new file mode 100644 index 0000000000..db091b3a59 --- /dev/null +++ b/files/es/web/javascript/reference/global_objects/set/index.html @@ -0,0 +1,230 @@ +--- +title: Set +slug: Web/JavaScript/Referencia/Objetos_globales/Set +tags: + - ECMAScript 2015 + - JavaScript + - Object + - set +translation_of: Web/JavaScript/Reference/Global_Objects/Set +--- +<div>{{JSRef}}</div> + +<p>El objeto <strong><code>Set</code></strong> permite almacenar valores únicos de cualquier tipo, incluso {{Glossary("Primitive", "valores primitivos")}} u referencias a objetos.</p> + +<h2 id="Sintaxis">Sintaxis</h2> + +<pre class="syntaxbox">new Set([iterable]);</pre> + +<h3 id="Parámetros">Parámetros</h3> + +<dl> + <dt>iterable</dt> + <dd>Si un <a href="/en-US/docs/Web/JavaScript/Reference/Statements/for...of">objeto iterable </a>es pasado, todos sus elementos serán añadidos al nuevo Set. Si no se especifica este parámetro, o si su valor es <code>null,</code> el nuevo <code>Set</code> estará vacío.</dd> +</dl> + +<h3 id="Valor_retornado">Valor retornado</h3> + +<p>Una nueva instancia de <code>Set</code>.</p> + +<h2 id="Descripción">Descripción</h2> + +<p>Los objetos <code><strong>Set</strong></code> son colecciones de valores. Se puede iterar sus elementos en el orden de su inserción. Un valor en un <code>Set</code> <strong>sólo puede estar una vez</strong>; éste es único en la colección <code>Set</code>.</p> + +<h3 id="Igualdad_de_valores">Igualdad de valores</h3> + +<p>Ya que cada valor en el Set tiene que ser único, la igualdad del valor será comprobada y esta igualdad no se basa en el mismo algoritmo usado en el operador <code>===</code>. Específicamente, para Sets, <code>+0</code> (el cual es estrictamente igual a <code>-0</code>) y <code>-0</code> son valores distintos. Sin embargo, esto ha cambiado en la última especificación ECMAScript 6. Iniciando con Gecko 29.0 {{geckoRelease("29")}} ({{bug("952870")}}) y un <a href="https://code.google.com/p/v8/issues/detail?id=3069">recent nightly Chrome</a>, <code>+0</code> y <code>-0</code> son tratados como el mismo valor en objetos <code>Set</code>. </p> + +<p><code>NaN</code> y <code>undefined</code> también pueden ser almacenados en un Set. <code>NaN</code> es considerado igual que <code>NaN</code> (A pesar que <code>NaN !== NaN</code>).</p> + +<h2 id="Propiedades">Propiedades</h2> + +<dl> + <dt><code>Set.length</code></dt> + <dd>El valor de la propiedad <code>length</code> es 0.</dd> + <dt>{{jsxref("Set.@@species", "get Set[@@species]")}}</dt> + <dd>La función constructora que es usada para crear objetos derivados.</dd> + <dt>{{jsxref("Set.prototype")}}</dt> + <dd>Representa el prototipo para el constructor Set. Permite la adición de propiedades a todos los objetos Set.</dd> +</dl> + +<h2 id="Instancias_Set">Instancias <code>Set</code></h2> + +<p>Todas las instancias de <code>Set</code> heredan de {{jsxref("Set.prototype")}}.</p> + +<h3 id="Propiedades_2">Propiedades</h3> + +<p>{{page('en-US/Web/JavaScript/Reference/Global_Objects/Set/prototype','Properties')}}</p> + +<h3 id="Métodos">Métodos</h3> + +<p>{{page('en-US/Web/JavaScript/Reference/Global_Objects/Set/prototype','Methods')}}</p> + +<h2 id="Ejemplos">Ejemplos</h2> + +<h3 id="Usando_el_objeto_Set">Usando el objeto <code>Set</code></h3> + +<pre class="brush: js">const mySet = new Set(); + +mySet.add(1); +mySet.add(5); +mySet.add('some text'); + +const o = {a: 1, b: 2}; +mySet.add(o); + +<code>mySet.add({a: 1, b: 2}); // La variable "o" referencia a otro objeto, por lo que agrega otro valor. +</code> +mySet.has(1); // true +mySet.has(3); // false, 3 no ha sido añadido al Set +mySet.has(5); // true +mySet.has(Math.sqrt(25)); // true +mySet.has('Some Text'.toLowerCase()); // true +mySet.has(o); // true + +mySet.size; // 5 + +mySet.delete(5); // Elimina 5 del Set +mySet.has(5); // false, 5 fue eliminado + +mySet.size; // 4, sólo removimos un valor +<code>console.log(mySet);// Set {1, "some text", Object {a: 1, b: 2}, Object {a: 1, b: 2}}</code></pre> + +<h3 id="Iterando_los_Sets">Iterando los Sets</h3> + +<pre class="brush: js">// iterar todos los items de un set +// imprimir en consola los items en orden: 1, 'some text', {a: 1, b: 2} +for (let item of mySet) console.log(item); + +// imprimir en consola los items en orden: 1, 'some text', {a: 1, b: 2} +for (let item of mySet.keys()) console.log(item); + +// imprimir en consola los items en orden: 1, 'some text', {a: 1, b: 2} +for (let item of mySet.values()) console.log(item); + +// imprimir en consola los items en orden: 1, 'some text', {a: 1, b: 2} +//(key y value poseen en mismo valor en este caso) +for (let [key, value] of mySet.entries()) console.log(key); + +// crear un Array plano con los mismos valores, utilizando Array.from +const myArr = Array.from(mySet); // [1, 'some text', {a: 1, b: 2}] + +// también se puede utilizar para guardar elementos del DOM +mySet.add(document.body); +mySet.has(document.querySelector('body')); // true + +// crear un Array plano con los mismos valores, utilizando propagación +const mySet2 = new Set([1,2,3,4]); +mySet2.size; // 4 +[...mySet2]; // [1,2,3,4] + +// la intersección entre dos sets puede ser simulada con +const intersection = <code>new Set([...set1].filter(x => set2.has(x)));</code> + +<code>// la diferencia puede ser simulada con +const difference = new Set([...set1].filter(x => !set2.has(x)));</code> + +// Iteración utilizando forEach +mySet.forEach((value) => { + console.log(value); +}); + +// 1 +// 2 +// 3 +// 4</pre> + +<h3 id="Implementando_operaciones_básicas">Implementando operaciones básicas</h3> + +<pre class="brush: js line-numbers language-js"><code class="language-js">Set<span class="punctuation token">.</span>prototype<span class="punctuation token">.</span>isSuperset <span class="operator token">=</span> <span class="keyword token">function</span><span class="punctuation token">(</span>subset<span class="punctuation token">)</span> <span class="punctuation token">{</span> + <span class="keyword token">for</span> <span class="punctuation token">(</span><span class="keyword token">var</span> elem <span class="keyword token">of</span> subset<span class="punctuation token">)</span> <span class="punctuation token">{</span> + <span class="keyword token">if</span> <span class="punctuation token">(</span><span class="operator token">!</span><span class="keyword token">this</span><span class="punctuation token">.</span><span class="function token">has</span><span class="punctuation token">(</span>elem<span class="punctuation token">)</span><span class="punctuation token">)</span> <span class="punctuation token">{</span> + <span class="keyword token">return</span> <span class="keyword token">false</span><span class="punctuation token">;</span> + <span class="punctuation token">}</span> + <span class="punctuation token">}</span> + <span class="keyword token">return</span> <span class="keyword token">true</span><span class="punctuation token">;</span> +<span class="punctuation token">}</span> + +Set<span class="punctuation token">.</span>prototype<span class="punctuation token">.</span>union <span class="operator token">=</span> <span class="keyword token">function</span><span class="punctuation token">(</span>setB<span class="punctuation token">)</span> <span class="punctuation token">{</span> + <span class="keyword token">var</span> union <span class="operator token">=</span> <span class="keyword token">new</span> <span class="class-name token">Set</span><span class="punctuation token">(</span><span class="keyword token">this</span><span class="punctuation token">)</span><span class="punctuation token">;</span> + <span class="keyword token">for</span> <span class="punctuation token">(</span><span class="keyword token">var</span> elem <span class="keyword token">of</span> setB<span class="punctuation token">)</span> <span class="punctuation token">{</span> + union<span class="punctuation token">.</span><span class="function token">add</span><span class="punctuation token">(</span>elem<span class="punctuation token">)</span><span class="punctuation token">;</span> + <span class="punctuation token">}</span> + <span class="keyword token">return</span> union<span class="punctuation token">;</span> +<span class="punctuation token">}</span> + +Set<span class="punctuation token">.</span>prototype<span class="punctuation token">.</span>intersection <span class="operator token">=</span> <span class="keyword token">function</span><span class="punctuation token">(</span>setB<span class="punctuation token">)</span> <span class="punctuation token">{</span> + <span class="keyword token">var</span> intersection <span class="operator token">=</span> <span class="keyword token">new</span> <span class="class-name token">Set</span><span class="punctuation token">(</span><span class="punctuation token">)</span><span class="punctuation token">;</span> + <span class="keyword token">for</span> <span class="punctuation token">(</span><span class="keyword token">var</span> elem <span class="keyword token">of</span> setB<span class="punctuation token">)</span> <span class="punctuation token">{</span> + <span class="keyword token">if</span> <span class="punctuation token">(</span><span class="keyword token">this</span><span class="punctuation token">.</span><span class="function token">has</span><span class="punctuation token">(</span>elem<span class="punctuation token">)</span><span class="punctuation token">)</span> <span class="punctuation token">{</span> + intersection<span class="punctuation token">.</span><span class="function token">add</span><span class="punctuation token">(</span>elem<span class="punctuation token">)</span><span class="punctuation token">;</span> + <span class="punctuation token">}</span> + <span class="punctuation token">}</span> + <span class="keyword token">return</span> intersection<span class="punctuation token">;</span> +<span class="punctuation token">}</span> + +Set<span class="punctuation token">.</span>prototype<span class="punctuation token">.</span>difference <span class="operator token">=</span> <span class="keyword token">function</span><span class="punctuation token">(</span>setB<span class="punctuation token">)</span> <span class="punctuation token">{</span> + <span class="keyword token">var</span> difference <span class="operator token">=</span> <span class="keyword token">new</span> <span class="class-name token">Set</span><span class="punctuation token">(</span><span class="keyword token">this</span><span class="punctuation token">)</span><span class="punctuation token">;</span> + <span class="keyword token">for</span> <span class="punctuation token">(</span><span class="keyword token">var</span> elem <span class="keyword token">of</span> setB<span class="punctuation token">)</span> <span class="punctuation token">{</span> + difference<span class="punctuation token">.</span><span class="keyword token">delete</span><span class="punctuation token">(</span>elem<span class="punctuation token">)</span><span class="punctuation token">;</span> + <span class="punctuation token">}</span> + <span class="keyword token">return</span> difference<span class="punctuation token">;</span> +<span class="punctuation token">}</span> + +<span class="comment token">//Examples</span> +<span class="keyword token">var</span> setA <span class="operator token">=</span> <span class="keyword token">new</span> <span class="class-name token">Set</span><span class="punctuation 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><span class="punctuation token">,</span> + setB <span class="operator token">=</span> <span class="keyword token">new</span> <span class="class-name token">Set</span><span class="punctuation token">(</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="punctuation token">)</span><span class="punctuation token">,</span> + setC <span class="operator token">=</span> <span class="keyword token">new</span> <span class="class-name token">Set</span><span class="punctuation token">(</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="number token">5</span><span class="punctuation token">,</span><span class="number token">6</span><span class="punctuation token">]</span><span class="punctuation token">)</span><span class="punctuation token">;</span> + +setA<span class="punctuation token">.</span><span class="function token">isSuperset</span><span class="punctuation token">(</span>setB<span class="punctuation token">)</span><span class="punctuation token">;</span> <span class="comment token">// => true</span> +setA<span class="punctuation token">.</span><span class="function token">union</span><span class="punctuation token">(</span>setC<span class="punctuation token">)</span><span class="punctuation token">;</span> <span class="comment token">// => Set [1, 2, 3, 4, 5, 6]</span> +setA<span class="punctuation token">.</span><span class="function token">intersection</span><span class="punctuation token">(</span>setC<span class="punctuation token">)</span><span class="punctuation token">;</span> <span class="comment token">// => Set [3, 4]</span> +setA<span class="punctuation token">.</span><span class="function token">difference</span><span class="punctuation token">(</span>setC<span class="punctuation token">)</span><span class="punctuation token">;</span> <span class="comment token">// => Set [1, 2]</span></code></pre> + +<h3 id="Relación_con_los_objetos_Array">Relación con los objetos <code>Array</code></h3> + +<pre class="brush: js">const myArray = ['value1', 'value2', 'value3']; + +// Utiliza el constructor para para crear un set con el mismo contenido que un array +const mySet = new Set(myArray); + +mySet.has('value1'); // devuelve true + +// Utiliza la propagación para crear un array con los contenidos de un set +console.log([...mySet]); // Muestra lo mismo utilizando myArray</pre> + +<h2 id="Especificaciones">Especificaciones</h2> + +<table class="standard-table"> + <tbody> + <tr> + <th scope="col">Especificación</th> + <th scope="col">Estado</th> + <th scope="col">Comentario</th> + </tr> + <tr> + <td>{{SpecName('ES2015', '#sec-set-objects', 'Set')}}</td> + <td>{{Spec2('ES2015')}}</td> + <td>Definición inicial</td> + </tr> + <tr> + <td>{{SpecName('ESDraft', '#sec-set-objects', 'Set')}}</td> + <td>{{Spec2('ESDraft')}}</td> + <td></td> + </tr> + </tbody> +</table> + +<h2 id="Compatibilidad_de_navegadores">Compatibilidad de navegadores</h2> + +<div class="hidden">La tabla de compatibilidad en esta página es generada desde información estructurada. Si desea contribuir, por favor revise la información en <a href="https://github.com/mdn/browser-compat-data">https://github.com/mdn/browser-compat-data</a> y envie un pull request/merge request.</div> + +<p>{{Compat("javascript.builtins.Set")}}</p> + +<h2 id="Ver_también">Ver también</h2> + +<ul> + <li>{{jsxref("Map")}}</li> + <li>{{jsxref("WeakMap")}}</li> + <li>{{jsxref("WeakSet")}}</li> +</ul> |