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<refentry xmlns="http://docbook.org/ns/docbook" xml:id="function.str-replace">
<refnamediv>
<refname>str_replace</refname>
<refpurpose>Replace all occurrences of the search string with the replacement string</refpurpose>
</refnamediv>
<refsect1 role="description">
&reftitle.description;
<methodsynopsis>
<type>mixed</type><methodname>str_replace</methodname>
<methodparam><type>mixed</type><parameter>search</parameter></methodparam>
<methodparam><type>mixed</type><parameter>replace</parameter></methodparam>
<methodparam><type>mixed</type><parameter>subject</parameter></methodparam>
<methodparam choice="opt"><type>int</type><parameter role="reference">count</parameter></methodparam>
</methodsynopsis>
<para>
This function returns a string or an array with all occurrences of
<parameter>search</parameter> in <parameter>subject</parameter>
replaced with the given <parameter>replace</parameter> value.
</para>
<para>
If you don't need fancy replacing rules (like regular expressions), you
should always use this function instead of <function>preg_replace</function>.
</para>
</refsect1>
<refsect1 role="parameters">
&reftitle.parameters;
<para>
If <parameter>search</parameter> and <parameter>replace</parameter> are
arrays, then <function>str_replace</function> takes a value from each array
and uses them to search and replace on <parameter>subject</parameter>. If
<parameter>replace</parameter> has fewer values than
<parameter>search</parameter>, then an empty string is used for the rest of
replacement values. If <parameter>search</parameter> is an array and
<parameter>replace</parameter> is a string, then this replacement string is
used for every value of <parameter>search</parameter>. The converse would
not make sense, though.
</para>
<para>
If <parameter>search</parameter> or <parameter>replace</parameter>
are arrays, their elements are processed first to last.
</para>
<para>
<variablelist>
<varlistentry>
<term><parameter>search</parameter></term>
<listitem>
<para>
The value being searched for, otherwise known as the <emphasis>needle</emphasis>.
An array may be used to designate multiple needles.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><parameter>replace</parameter></term>
<listitem>
<para>
The replacement value that replaces found <parameter>search</parameter>
values. An array may be used to designate multiple replacements.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><parameter>subject</parameter></term>
<listitem>
<para>
The string or array being searched and replaced on,
otherwise known as the <emphasis>haystack</emphasis>.
</para>
<para>
If <parameter>subject</parameter> is an array, then the search and
replace is performed with every entry of
<parameter>subject</parameter>, and the return value is an array as
well.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><parameter>count</parameter></term>
<listitem>
<para>
If passed, this will be set to the number of replacements performed.
</para>
</listitem>
</varlistentry>
</variablelist>
</para>
</refsect1>
<refsect1 role="returnvalues">
&reftitle.returnvalues;
<para>
This function returns a string or an array with the replaced values.
</para>
</refsect1>
<refsect1 role="examples">
&reftitle.examples;
<para>
<example>
<title>Basic <function>str_replace</function> examples</title>
<programlisting role="php">
<![CDATA[
<?php
// Provides: <body text='black'>
$bodytag = str_replace("%body%", "black", "<body text='%body%'>");
// Provides: Hll Wrld f PHP
$vowels = array("a", "e", "i", "o", "u", "A", "E", "I", "O", "U");
$onlyconsonants = str_replace($vowels, "", "Hello World of PHP");
// Provides: You should eat pizza, beer, and ice cream every day
$phrase = "You should eat fruits, vegetables, and fiber every day.";
$healthy = array("fruits", "vegetables", "fiber");
$yummy = array("pizza", "beer", "ice cream");
$newphrase = str_replace($healthy, $yummy, $phrase);
// Provides: 2
$str = str_replace("ll", "", "good golly miss molly!", $count);
echo $count;
?>
]]>
</programlisting>
</example>
</para>
<para>
<example>
<title>Examples of potential <function>str_replace</function> gotchas</title>
<programlisting role="php">
<![CDATA[
<?php
// Order of replacement
$str = "Line 1\nLine 2\rLine 3\r\nLine 4\n";
$order = array("\r\n", "\n", "\r");
$replace = '<br />';
// Processes \r\n's first so they aren't converted twice.
$newstr = str_replace($order, $replace, $str);
// Outputs F because A is replaced with B, then B is replaced with C, and so on...
// Finally E is replaced with F, because of left to right replacements.
$search = array('A', 'B', 'C', 'D', 'E');
$replace = array('B', 'C', 'D', 'E', 'F');
$subject = 'A';
echo str_replace($search, $replace, $subject);
// Outputs: apearpearle pear
// For the same reason mentioned above
$letters = array('a', 'p');
$fruit = array('apple', 'pear');
$text = 'a p';
$output = str_replace($letters, $fruit, $text);
echo $output;
?>
]]>
</programlisting>
</example>
</para>
</refsect1>
<refsect1 role="notes">
&reftitle.notes;
¬e.bin-safe;
<caution>
<title>Replacement order gotcha</title>
<para>
Because <function>str_replace</function> replaces left to right, it might
replace a previously inserted value when doing multiple replacements.
See also the examples in this document.
</para>
</caution>
<note>
<para>
This function is case-sensitive. Use <function>str_ireplace</function>
for case-insensitive replace.
</para>
</note>
</refsect1>
<refsect1 role="seealso">
&reftitle.seealso;
<para>
<simplelist>
<member><function>str_ireplace</function></member>
<member><function>substr_replace</function></member>
<member><function>preg_replace</function></member>
<member><function>strtr</function></member>
</simplelist>
</para>
</refsect1>
</refentry>
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