---
title: 'null'
slug: Web/JavaScript/Reference/Global_Objects/null
translation_of: Web/JavaScript/Reference/Global_Objects/null
---
<div>{{jsSidebar("Objects")}}</div>

<p>De waarde <code>null</code> representeert het moedwillig weglaten, of de bedoelde afwezigheid van welk object of waarde dan ook. Het is een van JavaScript's {{Glossary("Primitive", "primitive values")}}.</p>

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

<pre class="syntaxbox"><code>null </code></pre>

<h2 id="Beschrijving">Beschrijving</h2>

<p>De waarde <code>null</code> wordt letterlijk geschreven als <code>null</code> (het is geen idenfifier voor een eigenschap van de global object zoals  {{jsxref("Global_Objects/undefined","undefined")}} wel kan zijn). In APIs, wordt <code>null</code> vaak verkregen op plekken waar een object mag worden verwacht, maar waar tegelijk geen object relevant is . Wanneer op null of undefined wordt gecontroleerd, wees dan bewust van de  <a href="/en-US/docs/Web/JavaScript/Reference/Operators/Comparison_Operators">verschillen tussen equality (==) en identity (===) operators</a> (type-conversie wordt via de eerste bereikt).</p>

<pre class="brush: js">// foo does not exist. It is not defined and has never been initialized:
&gt; foo
"ReferenceError: foo is not defined"

// foo is known to exist now but it has no type or value:
&gt; var foo = null; foo
"null"
</pre>

<h3 id="Verschil_tussen_null_en_undefined">Verschil tussen <code>null</code> en <code> undefined</code></h3>

<pre class="brush: js">typeof null        // object (bug in ECMAScript, should be null)
typeof undefined   // undefined
null === undefined // false
null  == undefined // true
</pre>

<h2 id="Specificaties">Specificaties</h2>

<table class="standard-table">
 <tbody>
  <tr>
   <th scope="col">Specificatie</th>
   <th scope="col">Status</th>
   <th scope="col">Commentaar</th>
  </tr>
  <tr>
   <td>{{SpecName('ES1')}}</td>
   <td>{{Spec2('ES1')}}</td>
   <td>Initial definition.</td>
  </tr>
  <tr>
   <td>{{SpecName('ES5.1', '#sec-4.3.11', 'null value')}}</td>
   <td>{{Spec2('ES5.1')}}</td>
   <td> </td>
  </tr>
  <tr>
   <td>{{SpecName('ES6', '#sec-null-value', 'null value')}}</td>
   <td>{{Spec2('ES6')}}</td>
   <td> </td>
  </tr>
  <tr>
   <td>{{SpecName('ESDraft', '#sec-null-value', 'null value')}}</td>
   <td>{{Spec2('ESDraft')}}</td>
   <td> </td>
  </tr>
 </tbody>
</table>

<h2 id="Browser_compatibiliteit">Browser compatibiliteit</h2>

<p>{{CompatibilityTable}}</p>

<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>{{CompatVersionUnknown}}</td>
   <td>{{CompatVersionUnknown}}</td>
   <td>{{CompatVersionUnknown}}</td>
   <td>{{CompatVersionUnknown}}</td>
   <td>{{CompatVersionUnknown}}</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>{{CompatVersionUnknown}}</td>
   <td>{{CompatVersionUnknown}}</td>
   <td>{{CompatVersionUnknown}}</td>
   <td>{{CompatVersionUnknown}}</td>
  </tr>
 </tbody>
</table>
</div>

<h2 id="Zie_ook">Zie ook</h2>

<ul>
 <li>{{jsxref("undefined")}}</li>
 <li>{{jsxref("NaN")}}</li>
</ul>