path: root/files/de/web/javascript/reference/global_objects/object/create/index.html

---
title: Object.create()
slug: Web/JavaScript/Reference/Global_Objects/Object/create
tags:
  - Methode(2)
  - Méthode
  - Objekt
  - Referenz
translation_of: Web/JavaScript/Reference/Global_Objects/Object/create
---
<div>{{JSRef("Global_Objects", "Object")}}</div>

<h2 id="Summary" name="Summary">Summary</h2>

<p>Die <code><strong>Object.create()</strong></code> Methode erstellt ein neues Objekt mit dem angegebenen Prototype object und ggf. zusätzlichen Eigenschaften (properties).</p>

<h2 id="Syntax" name="Syntax">Syntax</h2>

<pre class="syntaxbox"><code>Object.create(<var>proto</var>[, <var>propertiesObject</var>])</code></pre>

<h3 id="Parameters" name="Parameters">Parameter</h3>

<dl>
 <dt><code>proto</code></dt>
 <dd>Das Objekt, welches als Prototype object des zu erstellenden Objekts verwendet wird.</dd>
 <dt><code>propertiesObject</code></dt>
 <dd>Optional. Falls angegeben und nicht {{jsxref("Global_Objects/undefined", "undefined")}}, ein Objekt dessen aufzählbare eigene Eigenschaften (properties, d.h.: Eigenschaften, die für das Objekt selbst definiert wurden und nicht in der prototype chain) als Eigenschaften dem neu erstellten Objekt hinzugefügt werden.  Die Eigenschaften entsprechen dem zweiten Parameter von {{jsxref("Object.defineProperties()")}}.</dd>
</dl>

<h3 id="Rückgabewert">Rückgabewert</h3>

<p>Ein neu erzeugtes Objekt mit dem angegebenen Prototype object und den angebenenen Eigenschaften (properties).</p>

<h3 id="Throws" name="Throws">Ausnahmen</h3>

<p>Eine {{jsxref("Global_Objects/TypeError", "TypeError")}}-Ausnahme wird ausgelöst, wenn der <code>proto</code>-Parameter weder {{jsxref("Global_Objects/null", "null")}} noch ein Objekt ist.</p>

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

<h3 id="Example:_Classical_inheritance_with_Object.create" name="Example:_Classical_inheritance_with_Object.create">Beispiel: Klassenbasierte Vererbung mit <code>Object.create()</code></h3>

<p>Im folgenden sehen Sie ein Beispiel wie man <code>Object.create()</code> verwenden kann, um klassenbasierte Vererbung zu realisieren. JavaScript unterstützt nur einzelne Vererbung.</p>

<pre class="brush: js">// Shape - superclass
function Shape() {
  this.x = 0;
  this.y = 0;
}

// superclass method
Shape.prototype.move = function(x, y) {
  this.x += x;
  this.y += y;
  console.info('Shape moved.');
};

// Rectangle - subclass
function Rectangle() {
  Shape.call(this); // call super constructor.
}

// subclass extends superclass
Rectangle.prototype = Object.create(Shape.prototype);
Rectangle.prototype.constructor = Rectangle;

var rect = new Rectangle();

console.log('Is rect an instance of Rectangle? ' + (rect instanceof Rectangle)); // true
console.log('Is rect an instance of Shape? ' + (rect instanceof Shape)); // true
rect.move(1, 1); // Outputs, 'Shape moved.'
</pre>

<p>Wenn Sie von mehreren Objekten erben wollen, können mixins verwendet werden.</p>

<pre class="brush: js">function MyClass() {
  SuperClass.call(this);
  OtherSuperClass.call(this);
}

MyClass.prototype = Object.create(SuperClass.prototype); // inherit
mixin(MyClass.prototype, OtherSuperClass.prototype); // mixin

MyClass.prototype.myMethod = function() {
  // do a thing
};
</pre>

<p>Die <code>mixin</code> Funktion kopiert die Funktionen des superclass Prototypen in den subclass Prototyp. Die mixin Funktion muss vom Benutzer bereitgestellt werden. Ein Beispiel für eine mixin-ähnliche Funktion ist <a href="http://api.jquery.com/jQuery.extend/">jQuery.extend()</a>.</p>

<h3 id="Example:_Using_propertiesObject_argument_with_Object.create" name="Example:_Using_propertiesObject_argument_with_Object.create">Beispiel: Benutzung des <code>propertiesObject</code> Parameters von <code>Object.create()</code></h3>

<pre class="brush: js">var o;

// create an object with null as prototype
o = Object.create(null);


o = {};
// is equivalent to:
o = Object.create(Object.prototype);


// Example where we create an object with a couple of sample properties.
// (Note that the second parameter maps keys to *property descriptors*.)
o = Object.create(Object.prototype, {
  // foo is a regular 'value property'
  foo: { writable: true, configurable: true, value: 'hello' },
  // bar is a getter-and-setter (accessor) property
  bar: {
    configurable: false,
    get: function() { return 10; },
    set: function(value) { console.log('Setting `o.bar` to', value); }
/* with ES5 Accessors our code can look like this
    get function() { return 10; },
    set function(value) { console.log('setting `o.bar` to', value); } */
  }
});


function Constructor() {}
o = new Constructor();
// is equivalent to:
o = Object.create(Constructor.prototype);
// Of course, if there is actual initialization code in the
// Constructor function, the Object.create() cannot reflect it


// create a new object whose prototype is a new, empty object
// and a adding single property 'p', with value 42
o = Object.create({}, { p: { value: 42 } });

// by default properties ARE NOT writable, enumerable or configurable:
o.p = 24;
o.p;
// 42

o.q = 12;
for (var prop in o) {
  console.log(prop);
}
// 'q'

delete o.p;
// false

// to specify an ES3 property
o2 = Object.create({}, {
  p: {
    value: 42,
    writable: true,
    enumerable: true,
    configurable: true
  }
});
</pre>

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

<p>Dieser Polyfill deckt den Hauptanwendungsfall, die Erzeugung eines neuen Objektes für das ein Prototyp ausgewählt wurde, ab.</p>

<p>Bitte beachten Sie, dass dieses Polyfill im Gegensatz zum echten ES5 <code>Object.create</code> den Einsatz von <code>null</code> als Prototyp-Parameter aufgrund einer Einschränkung von ECMAScript vor Version 5 nicht unterstützt.</p>

<pre class="brush: js line-numbers  language-js"><code class="language-js"><span class="keyword token">if</span> <span class="punctuation token">(</span><span class="keyword token">typeof</span> Object<span class="punctuation token">.</span>create <span class="operator token">!=</span> <span class="string token">'function'</span><span class="punctuation token">)</span> <span class="punctuation token">{</span>
  Object<span class="punctuation token">.</span>create <span class="operator token">=</span> <span class="punctuation token">(</span><span class="keyword token">function</span><span class="punctuation token">(</span>undefined<span class="punctuation token">)</span> <span class="punctuation token">{</span>
    <span class="keyword token">var</span> Temp <span class="operator token">=</span> <span class="keyword token">function</span><span class="punctuation token">(</span><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> <span class="keyword token">function</span> <span class="punctuation token">(</span>prototype<span class="punctuation token">,</span> propertiesObject<span class="punctuation token">)</span> <span class="punctuation token">{</span>
      <span class="keyword token">if</span><span class="punctuation token">(</span>prototype <span class="operator token">!==</span> <span class="function token">Object</span><span class="punctuation token">(</span>prototype<span class="punctuation token">)</span> <span class="operator token">&amp;&amp;</span> prototype <span class="operator token">!==</span> <span class="keyword token">null</span><span class="punctuation token">)</span> <span class="punctuation token">{</span>
        <span class="keyword token">throw</span> <span class="function token">TypeError</span><span class="punctuation token">(</span><span class="string token">'Argument must be an object, or null'</span><span class="punctuation token">)</span><span class="punctuation token">;</span>
      <span class="punctuation token">}</span>
      Temp<span class="punctuation token">.</span>prototype <span class="operator token">=</span> prototype <span class="operator token">||</span> <span class="punctuation token">{</span><span class="punctuation token">}</span><span class="punctuation token">;</span>
      <span class="keyword token">if</span> <span class="punctuation token">(</span>propertiesObject <span class="operator token">!==</span> undefined<span class="punctuation token">)</span> <span class="punctuation token">{</span>
        Object<span class="punctuation token">.</span><span class="function token">defineProperties</span><span class="punctuation token">(</span>Temp<span class="punctuation token">.</span>prototype<span class="punctuation token">,</span> propertiesObject<span class="punctuation token">)</span><span class="punctuation token">;</span>
      <span class="punctuation token">}</span>
      <span class="keyword token">var</span> result <span class="operator token">=</span> <span class="keyword token">new</span> <span class="class-name token">Temp</span><span class="punctuation token">(</span><span class="punctuation token">)</span><span class="punctuation token">;</span>
      Temp<span class="punctuation token">.</span>prototype <span class="operator token">=</span> <span class="keyword token">null</span><span class="punctuation token">;</span>
      <span class="comment token">// to imitate the case of Object.create(null)</span>
      <span class="keyword token">if</span><span class="punctuation token">(</span>prototype <span class="operator token">===</span> <span class="keyword token">null</span><span class="punctuation token">)</span> <span class="punctuation token">{</span>
         result<span class="punctuation token">.</span>__proto__ <span class="operator token">=</span> <span class="keyword token">null</span><span class="punctuation token">;</span>
      <span class="punctuation token">}</span>
      <span class="keyword token">return</span> result<span class="punctuation token">;</span>
    <span class="punctuation token">}</span><span class="punctuation token">;</span>
  <span class="punctuation token">}</span><span class="punctuation token">)</span><span class="punctuation token">(</span><span class="punctuation token">)</span><span class="punctuation token">;</span>
<span class="punctuation token">}</span></code></pre>

<h2 id="Specifications" name="Specifications">Spezifikationen</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('ES5.1', '#sec-15.2.3.5', 'Object.create')}}</td>
   <td>{{Spec2('ES5.1')}}</td>
   <td>Initial definition. Implemented in JavaScript 1.8.5.</td>
  </tr>
  <tr>
   <td>{{SpecName('ES6', '#sec-object.create', 'Object.create')}}</td>
   <td>{{Spec2('ES6')}}</td>
   <td> </td>
  </tr>
 </tbody>
</table>

<h2 id="Browser_compatibility" name="Browser_compatibility">Browser Kompatibilität</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>Opera</th>
   <th>Safari</th>
  </tr>
  <tr>
   <td>Basic support</td>
   <td>{{CompatChrome("5")}}</td>
   <td>{{CompatGeckoDesktop("2")}}</td>
   <td>{{CompatIE("9")}}</td>
   <td>{{CompatOpera("11.60")}}</td>
   <td>{{CompatSafari("5")}}</td>
  </tr>
 </tbody>
</table>
</div>

<div id="compat-mobile">
<table class="compat-table">
 <tbody>
  <tr>
   <th>Feature</th>
   <th>Android</th>
   <th>Chrome for Android</th>
   <th>Firefox Mobile (Gecko)</th>
   <th>IE Mobile</th>
   <th>Opera Mobile</th>
   <th>Safari Mobile</th>
  </tr>
  <tr>
   <td>Basic support</td>
   <td>{{CompatVersionUnknown}}</td>
   <td>{{CompatVersionUnknown}}</td>
   <td>{{CompatGeckoDesktop("2")}}</td>
   <td>{{CompatVersionUnknown}}</td>
   <td>{{CompatOperaMobile("11.50")}}</td>
   <td>{{CompatVersionUnknown}}</td>
  </tr>
 </tbody>
</table>
</div>

<p>Basierend auf <a href="http://kangax.github.com/es5-compat-table/">Kangax's compat table</a>.</p>

<h2 id="See_also" name="See_also">Zusätzliches Material</h2>

<ul>
 <li>{{jsxref("Object.defineProperty()")}}</li>
 <li>{{jsxref("Object.defineProperties()")}}</li>
 <li>{{jsxref("Object.prototype.isPrototypeOf()")}}</li>
 <li>John Resig's post on <a href="http://ejohn.org/blog/objectgetprototypeof/">getPrototypeOf()</a></li>
</ul>