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https://github.com/sigmasternchen/php-doc-en
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3ef3e56c80
* Rewrite count() page * Change methodname to interface name and fix example output * Add example with Countable object * Delete redundant code comments
272 lines
6.6 KiB
XML
272 lines
6.6 KiB
XML
<?xml version="1.0" encoding="utf-8"?>
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<!-- $Revision$ -->
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<refentry xml:id="function.count" xmlns="http://docbook.org/ns/docbook">
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<refnamediv>
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<refname>count</refname>
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<refpurpose>Counts all elements in an array or in a <interfacename>Countable</interfacename> object</refpurpose>
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</refnamediv>
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<refsect1 role="description">
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&reftitle.description;
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<methodsynopsis>
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<type>int</type><methodname>count</methodname>
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<methodparam><type class="union"><type>Countable</type><type>array</type></type><parameter>value</parameter></methodparam>
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<methodparam choice="opt"><type>int</type><parameter>mode</parameter><initializer><constant>COUNT_NORMAL</constant></initializer></methodparam>
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</methodsynopsis>
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<para>
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Counts all elements in an array when used with an array. When used with an
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object that implements the <interfacename>Countable</interfacename> interface, it returns
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the return value of the method <methodname>Countable::count</methodname>.
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</para>
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</refsect1>
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<refsect1 role="parameters">
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&reftitle.parameters;
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<para>
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<variablelist>
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<varlistentry>
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<term><parameter>value</parameter></term>
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<listitem>
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<para>
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An array or <interfacename>Countable</interfacename> object.
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</para>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term><parameter>mode</parameter></term>
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<listitem>
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<para>
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If the optional <parameter>mode</parameter> parameter is set to
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<constant>COUNT_RECURSIVE</constant> (or 1), <function>count</function>
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will recursively count the array. This is particularly useful for
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counting all the elements of a multidimensional array.
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</para>
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<caution>
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<para>
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<function>count</function> can detect recursion to avoid an infinite
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loop, but will emit an <constant>E_WARNING</constant> every time it
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does (in case the array contains itself more than once) and return a
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count higher than may be expected.
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</para>
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</caution>
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</listitem>
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</varlistentry>
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</variablelist>
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</para>
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</refsect1>
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<refsect1 role="returnvalues">
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&reftitle.returnvalues;
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<para>
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Returns the number of elements in <parameter>value</parameter>.
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Prior to PHP 8.0.0, if the parameter was neither an &array; nor an &object; that
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implements the <interfacename>Countable</interfacename> interface,
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<literal>1</literal> would be returned,
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unless <parameter>value</parameter> was &null;, in which case
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<literal>0</literal> would be returned.
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</para>
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</refsect1>
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<refsect1 role="changelog">
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&reftitle.changelog;
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<informaltable>
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<tgroup cols="2">
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<thead>
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<row>
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<entry>&Version;</entry>
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<entry>&Description;</entry>
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</row>
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</thead>
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<tbody>
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<row>
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<entry>8.0.0</entry>
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<entry>
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<function>count</function> will now throw <classname>TypeError</classname> on
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invalid countable types passed to the <parameter>value</parameter> parameter.
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</entry>
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</row>
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<row>
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<entry>7.2.0</entry>
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<entry>
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<function>count</function> will now yield a warning on invalid countable types
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passed to the <parameter>value</parameter> parameter.
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</entry>
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</row>
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</tbody>
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</tgroup>
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</informaltable>
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</refsect1>
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<refsect1 role="examples">
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&reftitle.examples;
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<para>
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<example xml:id="count.example.basic">
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<title><function>count</function> example</title>
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<programlisting role="php">
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<![CDATA[
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<?php
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$a[0] = 1;
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$a[1] = 3;
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$a[2] = 5;
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var_dump(count($a));
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$b[0] = 7;
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$b[5] = 9;
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$b[10] = 11;
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var_dump(count($b));
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?>
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]]>
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</programlisting>
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&example.outputs;
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<screen role="php">
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<![CDATA[
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int(3)
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int(3)
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]]>
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</screen>
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</example>
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</para>
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<para>
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<example xml:id="count.example.badexample">
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<title><function>count</function> non Countable|array example (bad example - don't do this)</title>
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<programlisting role="php">
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<![CDATA[
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<?php
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$b[0] = 7;
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$b[5] = 9;
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$b[10] = 11;
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var_dump(count($b));
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var_dump(count(null));
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var_dump(count(false));
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?>
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]]>
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</programlisting>
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&example.outputs;
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<screen role="php">
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<![CDATA[
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int(3)
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int(0)
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int(1)
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]]>
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</screen>
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&example.outputs.72;
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<screen role="php">
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<![CDATA[
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int(3)
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Warning: count(): Parameter must be an array or an object that implements Countable in … on line 12
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int(0)
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Warning: count(): Parameter must be an array or an object that implements Countable in … on line 14
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int(1)
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]]>
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</screen>
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&example.outputs.8;
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<screen role="php">
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<![CDATA[
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int(3)
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Fatal error: Uncaught TypeError: count(): Argument #1 ($var) must be of type Countable .. on line 12
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]]>
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</screen>
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</example>
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</para>
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<para>
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<example xml:id="count.example.recursive">
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<title>Recursive <function>count</function> example</title>
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<programlisting role="php">
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<![CDATA[
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<?php
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$food = array('fruits' => array('orange', 'banana', 'apple'),
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'veggie' => array('carrot', 'collard', 'pea'));
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// recursive count
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var_dump(count($food, COUNT_RECURSIVE));
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// normal count
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var_dump(count($food));
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?>
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]]>
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</programlisting>
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&example.outputs;
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<screen role="php">
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<![CDATA[
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int(8)
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int(2)
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]]>
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</screen>
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</example>
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</para>
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<para>
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<example xml:id="count.example.countable">
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<title><interfacename>Countable</interfacename> object</title>
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<programlisting role="php">
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<![CDATA[
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<?php
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class CountOfMethods implements Countable
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{
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private function someMethod()
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{
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}
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public function count(): int
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{
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return count(get_class_methods($this));
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}
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}
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$obj = new CountOfMethods();
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var_dump(count($obj));
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?>
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]]>
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</programlisting>
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&example.outputs;
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<screen role="php">
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<![CDATA[
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int(2)
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]]>
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</screen>
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</example>
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</para>
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</refsect1>
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<refsect1 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_array</function></member>
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<member><function>isset</function></member>
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<member><function>empty</function></member>
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<member><function>strlen</function></member>
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<member><function>is_countable</function></member>
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<member><link linkend="language.types.array">Arrays</link></member>
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</simplelist>
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</para>
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</refsect1>
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</refentry>
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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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sgml-omittag:t
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sgml-shorttag:t
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sgml-minimize-attributes:nil
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sgml-always-quote-attributes:t
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sgml-indent-step:1
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sgml-indent-data:t
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indent-tabs-mode:nil
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sgml-parent-document:nil
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sgml-default-dtd-file:"~/.phpdoc/manual.ced"
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sgml-exposed-tags:nil
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sgml-local-catalogs:nil
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sgml-local-ecat-files:nil
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End:
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vim600: syn=xml fen fdm=syntax fdl=2 si
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vim: et tw=78 syn=sgml
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vi: ts=1 sw=1
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-->
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