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<?xml version="1.0" encoding="utf-8"?>
<!-- $Revision$ -->
<refentry xml:id="function.strrpos" xmlns="http://docbook.org/ns/docbook">
<refnamediv>
<refname>strrpos</refname>
<refpurpose>Find the position of the last occurrence of a substring in a string</refpurpose>
</refnamediv>
<refsect1 role="description">
&reftitle.description;
<methodsynopsis>
<type class="union"><type>int</type><type>false</type></type><methodname>strrpos</methodname>
<methodparam><type>string</type><parameter>haystack</parameter></methodparam>
<methodparam><type>string</type><parameter>needle</parameter></methodparam>
<methodparam choice="opt"><type>int</type><parameter>offset</parameter><initializer>0</initializer></methodparam>
</methodsynopsis>
<para>
Find the numeric position of the last occurrence of
<parameter>needle</parameter> in the <parameter>haystack</parameter> string.
</para>
</refsect1>
<refsect1 role="parameters">
&reftitle.parameters;
<para>
<variablelist>
<varlistentry>
<term><parameter>haystack</parameter></term>
<listitem>
<para>
The string to search in.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><parameter>needle</parameter></term>
<listitem>
<para>
The string to search for.
</para>
&strings.parameter.needle.non-string;
</listitem>
</varlistentry>
<varlistentry>
<term><parameter>offset</parameter></term>
<listitem>
<para>
If zero or positive, the search is performed left to right skipping the
first <parameter>offset</parameter> bytes of the
<parameter>haystack</parameter>.
</para>
<para>
If negative, the search starts <parameter>offset</parameter> bytes from
the right instead of from the beginning of <parameter>haystack</parameter>.
The search is performed right to left, searching for the first
occurrence of <parameter>needle</parameter> from the selected byte.
<note>
<para>
This is effectively looking for the last occurrence of
<parameter>needle</parameter> at or before the last
<parameter>offset</parameter> bytes.
</para>
</note>
</para>
</listitem>
</varlistentry>
</variablelist>
</para>
</refsect1>
<refsect1 role="returnvalues">
&reftitle.returnvalues;
<para>
Returns the position where the needle exists relative to the beginning of
the <parameter>haystack</parameter> string (independent of search direction
or offset).
<note>
<simpara>
String positions start at 0, and not 1.
</simpara>
</note>
</para>
<para>
Returns &false; if the needle was not found.
</para>
&return.falseproblem;
</refsect1>
<refsect1 role="changelog">
&reftitle.changelog;
<informaltable>
<tgroup cols="2">
<thead>
<row>
<entry>&Version;</entry>
<entry>&Description;</entry>
</row>
</thead>
<tbody>
&strings.changelog.needle-empty;
<row>
<entry>8.0.0</entry>
<entry>
Passing an &integer; as <parameter>needle</parameter> is no longer supported.
</entry>
</row>
<row>
<entry>7.3.0</entry>
<entry>
Passing an &integer; as <parameter>needle</parameter> has been deprecated.
</entry>
</row>
</tbody>
</tgroup>
</informaltable>
</refsect1>
<refsect1 role="examples">
&reftitle.examples;
<para>
<example>
<title>Checking if a needle is in the haystack</title>
<para>
It is easy to mistake the return values for "character found at
position 0" and "character not found". Here's how to detect
the difference:
</para>
<programlisting role="php">
<![CDATA[
<?php
$pos = strrpos($mystring, "b");
if ($pos === false) { // note: three equal signs
// not found...
}
?>
]]>
</programlisting>
</example>
</para>
<para>
<example>
<title>Searching with offsets</title>
<programlisting role="php">
<![CDATA[
<?php
$foo = "0123456789a123456789b123456789c";
// Looking for '0' from the 0th byte (from the beginning)
var_dump(strrpos($foo, '0', 0));
// Looking for '0' from the 1st byte (after byte "0")
var_dump(strrpos($foo, '0', 1));
// Looking for '7' from the 21th byte (after byte 20)
var_dump(strrpos($foo, '7', 20));
// Looking for '7' from the 29th byte (after byte 28)
var_dump(strrpos($foo, '7', 28));
// Looking for '7' right to left from the 5th byte from the end
var_dump(strrpos($foo, '7', -5));
// Looking for 'c' right to left from the 2nd byte from the end
var_dump(strrpos($foo, 'c', -2));
// Looking for '9c' right to left from the 2nd byte from the end
var_dump(strrpos($foo, '9c', -2));
?>
]]>
</programlisting>
&example.outputs;
<screen>
<![CDATA[
int(0)
bool(false)
int(27)
bool(false)
int(17)
bool(false)
int(29)
]]>
</screen>
</example>
</para>
</refsect1>
<refsect1 role="seealso">
&reftitle.seealso;
<para>
<simplelist>
<member><function>strpos</function></member>
<member><function>stripos</function></member>
<member><function>strripos</function></member>
<member><function>strrchr</function></member>
<member><function>substr</function></member>
</simplelist>
</para>
</refsect1>
</refentry>
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