<documentation title="Uppercase PHP Constants">
<standard>
<![CDATA[
The <em>true</em>, <em>false</em> and <em>null</em> constants must always be uppercase.
]]>
</standard>
<code_comparison>
<code title="Valid: uppercase constants">
<![CDATA[
if ($var === <em>FALSE</em> || $var === <em>NULL</em>) {
$var = <em>TRUE</em>;
}
]]>
</code>
<code title="Invalid: lowercase constants">
<![CDATA[
if ($var === <em>false</em> || $var === <em>null</em>) {
$var = <em>true</em>;
}
]]>
</code>
</code_comparison>
</documentation>