Revision 984231 of ReferenceError

<div>{{JSRef}}</div>

<p>The <code><strong>ReferenceError</strong></code> object represents an error when a non-existent variable is referenced.</p>

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

<pre class="syntaxbox">
<code>new ReferenceError([<var>message</var>[, <var>fileName</var>[, <var>lineNumber</var>]]])</code></pre>

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

<dl>
 <dt><code>message</code></dt>
 <dd>Optional. Human-readable description of the error</dd>
 <dt><code>fileName</code> {{non-standard_inline}}</dt>
 <dd>Optional. The name of the file containing the code that caused the exception</dd>
 <dt><code>lineNumber</code> {{non-standard_inline}}</dt>
 <dd>Optional. The line number of the code that caused the exception</dd>
</dl>

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

<p>A <code>ReferenceError</code> is thrown when trying to dereference a variable that has not been declared.</p>

<h2 id="Properties">Properties</h2>

<dl>
 <dt>{{jsxref("ReferenceError.prototype")}}</dt>
 <dd>Allows the addition of properties to an <code>ReferenceError</code> object.</dd>
</dl>

<h2 id="Methods">Methods</h2>

<p>The global <code>ReferenceError</code> contains no methods of its own, however, it does inherit some methods through the prototype chain.</p>

<h2 id="ReferenceError_instances"><code>ReferenceError</code> instances</h2>

<h3 id="Properties_2">Properties</h3>

<div>{{page('/en-US/docs/Web/JavaScript/Reference/Global_Objects/ReferenceError/prototype', 'Properties')}}</div>

<h3 id="Methods_2">Methods</h3>

<div>{{page('/en-US/docs/Web/JavaScript/Reference/Global_Objects/ReferenceError/prototype', 'Methods')}}</div>

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

<h3 id="Catching_a_ReferenceError">Catching a <code>ReferenceError</code></h3>

<pre class="brush: js">
try {
  var a = undefinedVariable;
} catch (e) {
  console.log(e instanceof ReferenceError); // true
  console.log(e.message);                   // "undefinedVariable is not defined"
  console.log(e.name);                      // "ReferenceError"
  console.log(e.fileName);                  // "Scratchpad/1"
  console.log(e.lineNumber);                // 2
  console.log(e.columnNumber);              // 6
  console.log(e.stack);                     // "@Scratchpad/2:2:7\n"
}
</pre>

<h3 id="Creating_a_ReferenceError">Creating a <code>ReferenceError</code></h3>

<pre class="brush: js">
try {
  throw new ReferenceError('Hello', 'someFile.js', 10);
} catch (e) {
  console.log(e instanceof ReferenceError); // true
  console.log(e.message);                   // "Hello"
  console.log(e.name);                      // "ReferenceError"
  console.log(e.fileName);                  // "someFile.js"
  console.log(e.lineNumber);                // 10
  console.log(e.columnNumber);              // 0
  console.log(e.stack);                     // "@Scratchpad/2:2:9\n"
}
</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('ES3')}}</td>
   <td>{{Spec2('ES3')}}</td>
   <td>Initial definition.</td>
  </tr>
  <tr>
   <td>{{SpecName('ES5.1', '#sec-15.11.6.3', 'ReferenceError')}}</td>
   <td>{{Spec2('ES5.1')}}</td>
   <td>&nbsp;</td>
  </tr>
  <tr>
   <td>{{SpecName('ES6', '#sec-native-error-types-used-in-this-standard-referenceerror', 'ReferenceError')}}</td>
   <td>{{Spec2('ES6')}}</td>
   <td>&nbsp;</td>
  </tr>
  <tr>
   <td>{{SpecName('ESDraft', '#sec-native-error-types-used-in-this-standard-referenceerror', 'ReferenceError')}}</td>
   <td>{{Spec2('ESDraft')}}</td>
   <td>&nbsp;</td>
  </tr>
 </tbody>
</table>

<h2 id="Browser_compatibility">Browser compatibility</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>{{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="See_also">See also</h2>

<ul>
 <li>{{jsxref("Error")}}</li>
 <li>{{jsxref("ReferenceError.prototype")}}</li>
</ul>