<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<title>Free all session variables</title>
</head>
<body><div class="manualnavbar" style="text-align: center;">
<div class="prev" style="text-align: left; float: left;"><a href="function.session-unregister.html">session_unregister</a></div>
<div class="next" style="text-align: right; float: right;"><a href="function.session-write-close.html">session_write_close</a></div>
<div class="up"><a href="ref.session.html">Session Functions</a></div>
<div class="home"><a href="index.html">PHP Manual</a></div>
</div><hr /><div id="function.session-unset" class="refentry">
<div class="refnamediv">
<h1 class="refname">session_unset</h1>
<p class="verinfo">(PHP 4, PHP 5, PHP 7)</p><p class="refpurpose"><span class="refname">session_unset</span> — <span class="dc-title">Free all session variables</span></p>
</div>
<div class="refsect1 description" id="refsect1-function.session-unset-description">
<h3 class="title">Description</h3>
<div class="methodsynopsis dc-description">
<span class="type">bool</span> <span class="methodname"><strong>session_unset</strong></span>
( <span class="methodparam">void</span>
)</div>
<p class="para rdfs-comment">
The <span class="function"><strong>session_unset()</strong></span> function frees all session variables
currently registered.
</p>
</div>
<div class="refsect1 returnvalues" id="refsect1-function.session-unset-returnvalues">
<h3 class="title">Return Values</h3>
<p class="para">
Returns <strong><code>TRUE</code></strong> on success or <strong><code>FALSE</code></strong> on failure.
</p>
</div>
<div class="refsect1 changelog" id="refsect1-function.session-unset-changelog">
<h3 class="title">Changelog</h3>
<table class="doctable informaltable">
<thead>
<tr>
<th>Version</th>
<th>Description</th>
</tr>
</thead>
<tbody class="tbody">
<tr>
<td>7.2.0</td>
<td>
The return type of this function is <span class="type"><a href="language.types.boolean.html" class="type bool">bool</a></span> now.
Formerly, it has been <span class="type"><span class="type void">void</span></span>.
</td>
</tr>
</tbody>
</table>
</div>
<div class="refsect1 notes" id="refsect1-function.session-unset-notes">
<h3 class="title">Notes</h3>
<blockquote class="note"><p><strong class="note">Note</strong>:
<p class="para">
If <var class="varname"><var class="varname"><a href="reserved.variables.session.html" class="classname">$_SESSION</a></var></var> is used, use <span class="function"><a href="function.unset.html" class="function">unset()</a></span> to
unregister a session variable, i.e.
<em>unset ($_SESSION['varname']);</em>.
</p>
</p></blockquote>
<div class="caution"><strong class="caution">Caution</strong>
<p class="para">
Do NOT unset the whole <var class="varname"><var class="varname"><a href="reserved.variables.session.html" class="classname">$_SESSION</a></var></var> with
<em>unset($_SESSION)</em> as this will disable the registering
of session variables through the <var class="varname"><var class="varname"><a href="reserved.variables.session.html" class="classname">$_SESSION</a></var></var> superglobal.
</p>
</div>
</div>
</div><hr /><div class="manualnavbar" style="text-align: center;">
<div class="prev" style="text-align: left; float: left;"><a href="function.session-unregister.html">session_unregister</a></div>
<div class="next" style="text-align: right; float: right;"><a href="function.session-write-close.html">session_write_close</a></div>
<div class="up"><a href="ref.session.html">Session Functions</a></div>
<div class="home"><a href="index.html">PHP Manual</a></div>
</div></body></html>
