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<h1 class="refname">Superglobals</h1>
<p class="refpurpose"><span class="refname">Superglobals</span> — <span class="dc-title">Superglobals are built-in variables that are always available in all scopes</span></p>
</div>
<div class="refsect1 description" id="refsect1-language.variables.superglobals-description">
<h3 class="title">Description</h3>
<p class="para">
Several predefined variables in PHP are "superglobals", which means they
are available in all scopes throughout a script. There is no need to do
<strong class="command">global $variable;</strong> to access them within functions
or methods.
</p>
<p class="para">
These superglobal variables are:
<ul class="simplelist">
<li class="member"><var class="varname"><var class="varname"><a href="reserved.variables.globals.html" class="classname">$GLOBALS</a></var></var></li>
<li class="member"><var class="varname"><var class="varname"><a href="reserved.variables.server.html" class="classname">$_SERVER</a></var></var></li>
<li class="member"><var class="varname"><var class="varname"><a href="reserved.variables.get.html" class="classname">$_GET</a></var></var></li>
<li class="member"><var class="varname"><var class="varname"><a href="reserved.variables.post.html" class="classname">$_POST</a></var></var></li>
<li class="member"><var class="varname"><var class="varname"><a href="reserved.variables.files.html" class="classname">$_FILES</a></var></var></li>
<li class="member"><var class="varname"><var class="varname"><a href="reserved.variables.cookies.html" class="classname">$_COOKIE</a></var></var></li>
<li class="member"><var class="varname"><var class="varname"><a href="reserved.variables.session.html" class="classname">$_SESSION</a></var></var></li>
<li class="member"><var class="varname"><var class="varname"><a href="reserved.variables.request.html" class="classname">$_REQUEST</a></var></var></li>
<li class="member"><var class="varname"><var class="varname"><a href="reserved.variables.environment.html" class="classname">$_ENV</a></var></var></li>
</ul>
</p>
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<div class="refsect1 changelog" id="refsect1-language.variables.superglobals-changelog">
<h3 class="title">Changelog</h3>
<p class="para">
<table class="doctable informaltable">
<thead>
<tr>
<th>Version</th>
<th>Description</th>
</tr>
</thead>
<tbody class="tbody">
<tr>
<td>4.1.0</td>
<td>
Superglobals were introduced to PHP.
</td>
</tr>
</tbody>
</table>
</p>
</div>
<div class="refsect1 notes" id="refsect1-language.variables.superglobals-notes">
<h3 class="title">Notes</h3>
<blockquote class="note"><p><strong class="note">Note</strong>:
<strong>Variable availability</strong><br />
<p class="para">
By default, all of the superglobals are available but there are
directives that affect this availability. For further information, refer
to the documentation for
<a href="ini.core.html#ini.variables-order" class="link">variables_order</a>.
</p>
</p></blockquote>
<blockquote class="note"><p><strong class="note">Note</strong>:
<strong>Dealing with register_globals</strong><br />
<p class="para">
If the deprecated <a href="ini.core.html#ini.register-globals" class="link">register_globals</a>
directive is set to <em>on</em> then the variables within will
also be made available in the global scope of the script. For example,
<var class="varname"><var class="varname"><a href="reserved.variables.post.html" class="classname">$_POST['foo']</a></var></var> would also exist as <var class="varname"><var class="varname">$foo</var></var>.
</p>
<p class="para">
For related information, see the FAQ titled
"<a href="faq.using.html#faq.register-globals" class="link">How does register_globals affect me?</a>"
</p>
</p></blockquote>
<blockquote class="note"><p><strong class="note">Note</strong>:
<strong>Variable variables</strong><br />
<p class="para">
Superglobals cannot be used as
<a href="language.variables.variable.html" class="link">variable variables</a>
inside functions or class methods.
</p>
</p></blockquote>
</div>
<div class="refsect1 seealso" id="refsect1-language.variables.superglobals-seealso">
<h3 class="title">See Also</h3>
<p class="para">
<ul class="simplelist">
<li class="member"><a href="language.variables.scope.html" class="link">variable scope</a></li>
<li class="member">The <a href="ini.core.html#ini.variables-order" class="link">variables_order</a> directive</li>
<li class="member"><a href="book.filter.html" class="link">The filter extension</a></li>
</ul>
</p>
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