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---
title: String.prototype.codePointAt()
slug: Web/JavaScript/Reference/Global_Objects/String/codePointAt
translation_of: Web/JavaScript/Reference/Global_Objects/String/codePointAt
original_slug: Web/JavaScript/Referencia/Objetos_globales/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 < 0 || index >= 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 >= 0xD800 && first <= 0xDBFF && // high surrogate
size > index + 1 // there is a next code unit
) {
second = string.charCodeAt(index + 1);
if (second >= 0xDC00 && second <= 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>
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