---
title: String.prototype.codePointAt()
slug: Web/JavaScript/Referencia/Objetos_globales/String/codePointAt
translation_of: Web/JavaScript/Reference/Global_Objects/String/codePointAt
---
<div>{{JSRef}}</div>

<div> </div>

<div>El método <strong><code>codePointAt() </code></strong><code>d</code>evuelve un entero no negativo que equivale al valor Unicode code point del carácter.</div>

<h2 id="Sintaxis">Sintaxis</h2>

<pre class="syntaxbox"><code><var>str</var>.codePointAt(<var>indice</var>)</code></pre>

<h3 id="Parámetros">Parámetros</h3>

<dl>
 <dt><code>indice</code></dt>
 <dd>Índice del carácter en la cadena del que se quiere obtener el valor del Unicode code point.</dd>
</dl>

<h3 id="Valor_de_retorno">Valor de retorno</h3>

<p>Un número que equivale al valor code point del carácter especificado en el índice de la cadena; devuelve {{jsxref("undefined")}} si no se encuentra carácter en la posición especifica.</p>

<h2 id="Description">Description</h2>

<p>If there is no element at the specified position, {{jsxref("undefined")}} is returned. If no UTF-16 surrogate pair begins at <code>pos</code>, the code unit at <code>pos</code> is returned.</p>

<h2 id="Examples">Examples</h2>

<h3 id="Using_codePointAt()">Using <code>codePointAt()</code></h3>

<pre class="brush: js">'ABC'.codePointAt(1);          // 66
'\uD800\uDC00'.codePointAt(0); // 65536

'XYZ'.codePointAt(42); // undefined
</pre>

<h2 id="Polyfill">Polyfill</h2>

<p>The following extends Strings to include the <code>codePointAt()</code> function as specified in ECMAScript 2015 for browsers not supporting it natively.</p>

<pre class="brush: js">/*! http://mths.be/codepointat v0.1.0 by @mathias */
if (!String.prototype.codePointAt) {
  (function() {
    'use strict'; // needed to support `apply`/`call` with `undefined`/`null`
    var codePointAt = function(position) {
      if (this == null) {
        throw TypeError();
      }
      var string = String(this);
      var size = string.length;
      // `ToInteger`
      var index = position ? Number(position) : 0;
      if (index != index) { // better `isNaN`
        index = 0;
      }
      // Account for out-of-bounds indices:
      if (index &lt; 0 || index &gt;= size) {
        return undefined;
      }
      // Get the first code unit
      var first = string.charCodeAt(index);
      var second;
      if ( // check if it’s the start of a surrogate pair
        first &gt;= 0xD800 &amp;&amp; first &lt;= 0xDBFF &amp;&amp; // high surrogate
        size &gt; index + 1 // there is a next code unit
      ) {
        second = string.charCodeAt(index + 1);
        if (second &gt;= 0xDC00 &amp;&amp; second &lt;= 0xDFFF) { // low surrogate
          // http://mathiasbynens.be/notes/javascript-encoding#surrogate-formulae
          return (first - 0xD800) * 0x400 + second - 0xDC00 + 0x10000;
        }
      }
      return first;
    };
    if (Object.defineProperty) {
      Object.defineProperty(String.prototype, 'codePointAt', {
        'value': codePointAt,
        'configurable': true,
        'writable': true
      });
    } else {
      String.prototype.codePointAt = codePointAt;
    }
  }());
}
</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('ES2015', '#sec-string.prototype.codepointat', 'String.prototype.codePointAt')}}</td>
   <td>{{Spec2('ES2015')}}</td>
   <td>Initial definition.</td>
  </tr>
  <tr>
   <td>{{SpecName('ESDraft', '#sec-string.prototype.codepointat', 'String.prototype.codePointAt')}}</td>
   <td>{{Spec2('ESDraft')}}</td>
   <td> </td>
  </tr>
 </tbody>
</table>

<h2 id="Browser_compatibility">Browser compatibility</h2>

<p class="hidden">The compatibility table in this page is generated from structured data. If you'd like to contribute to the data, please check out <a href="https://github.com/mdn/browser-compat-data">https://github.com/mdn/browser-compat-data</a> and send us a pull request.</p>

<p>{{Compat("javascript.builtins.String.codePointAt")}}</p>

<h2 id="See_also">See also</h2>

<ul>
 <li>{{jsxref("String.fromCodePoint()")}}</li>
 <li>{{jsxref("String.fromCharCode()")}}</li>
 <li>{{jsxref("String.prototype.charCodeAt()")}}</li>
 <li>{{jsxref("String.prototype.charAt()")}}</li>
</ul>