Unsere Freiwilligen haben diesen Artikel noch nicht in Deutsch übersetzt. Machen Sie mit und helfen Sie, das zu erledigen!
Sie können den Artikel auch auf English (US) lesen.

The codePointAt() method returns a non-negative integer that is the Unicode code point value.




Position of an element in the String to return the code point value from.

Return value

A number representing the code point value of the character at the given index; undefined if there is no element at pos.


If there is no element at the specified position, undefined is returned. If no UTF-16 surrogate pair begins at pos, the code unit at pos is returned.


Using codePointAt()

'ABC'.codePointAt(1);          // 66
'\uD800\uDC00'.codePointAt(0); // 65536

'XYZ'.codePointAt(42); // undefined


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

/*! https://mths.be/codepointat v0.2.0 by @mathias */
if (!String.prototype.codePointAt) {
  (function() {
    'use strict'; // needed to support `apply`/`call` with `undefined`/`null`
    var defineProperty = (function() {
      // IE 8 only supports `Object.defineProperty` on DOM elements
      try {
        var object = {};
        var $defineProperty = Object.defineProperty;
        var result = $defineProperty(object, object, object) && $defineProperty;
      } catch(error) {}
      return result;
    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
          // https://mathiasbynens.be/notes/javascript-encoding#surrogate-formulae
          return (first - 0xD800) * 0x400 + second - 0xDC00 + 0x10000;
      return first;
    if (defineProperty) {
      defineProperty(String.prototype, 'codePointAt', {
        'value': codePointAt,
        'configurable': true,
        'writable': true
    } else {
      String.prototype.codePointAt = codePointAt;


Specification Status Comment
ECMAScript 2015 (6th Edition, ECMA-262)
The definition of 'String.prototype.codePointAt' in that specification.
Standard Initial definition.
ECMAScript Latest Draft (ECMA-262)
The definition of 'String.prototype.codePointAt' in that specification.

Browser compatibility

Update compatibility data on GitHub
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidEdge MobileFirefox for AndroidOpera for AndroidSafari on iOSSamsung InternetNode.js
codePointAtChrome Full support 41Edge Full support 12Firefox Full support 29IE No support NoOpera Full support 28Safari Full support 10WebView Android Full support YesChrome Android Full support YesEdge Mobile Full support YesFirefox Android Full support 29Opera Android Full support YesSafari iOS Full support 10Samsung Internet Android Full support Yesnodejs Full support 4.0.0
Full support 4.0.0
Full support 0.12
Disabled From version 0.12: this feature is behind the --harmony runtime flag.


Full support  
Full support
No support  
No support
User must explicitly enable this feature.
User must explicitly enable this feature.

See also

Schlagwörter des Dokuments und Mitwirkende

Zuletzt aktualisiert von: mdnwebdocs-bot,