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@@ -4,32 +4,15 @@

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<title>NULL</title>

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<para>

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The special &null; value represents a variable with no value. &null; is the

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only possible value of type <type>null</type>.

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The <type>null</type> type is PHP's unit type, i.e. it has only one value:

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&null;.

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</para>

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<para>

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A variable is considered to be <type>null</type> if:

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Undefined, and <function>unset</function> variables will resolve to the

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value &null;.

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</para>

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<itemizedlist>

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<listitem>

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<para>

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it has been assigned the constant &null;.

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</para>

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</listitem>

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<listitem>

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<para>

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it has not been set to any value yet.

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</para>

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</listitem>

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<listitem>

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<para>

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it has been <function>unset</function>.

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</para>

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</listitem>

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</itemizedlist>

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<sect2 xml:id="language.types.null.syntax">

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<title>Syntax</title>

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...

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@@ -47,18 +30,16 @@ $var = NULL;

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]]>

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</programlisting>

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</informalexample>

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<para>

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See also the functions <function>is_null</function> and

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<function>unset</function>.

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</para>

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</sect2>

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<sect2 xml:id="language.types.null.casting">

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<title>Casting to &null;</title>

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<para>

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&warn.deprecated.feature-7-2-0.removed-8-0-0;

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</para>

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<para>

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Casting a variable to <type>null</type> using <literal>(unset) $var</literal>

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will <emphasis>not</emphasis> remove the variable or unset its value.

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It will only return a &null; value.

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@@ -66,8 +47,17 @@ $var = NULL;

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</sect2>

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</sect1>

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<sect2 role="seealso">

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&reftitle.seealso;

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<para>

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<simplelist>

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<member><function>is_null</function></member>

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<member><function>unset</function></member>

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</simplelist>

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</para>

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</sect2>

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</sect1>

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<!-- Keep this comment at the end of the file

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Local variables:

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mode: sgml

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