php-doc-en/reference/array/functions/each.xml
Andrey Andreev 028513e94b Document PHP 7.2 deprecations as the result of https://wiki.php.net/rfc/deprecations_php_7_2
Also, simplify the first paragraph of 'Traditional assertions' in assert() docs

git-svn-id: https://svn.php.net/repository/phpdoc/en/trunk@342126 c90b9560-bf6c-de11-be94-00142212c4b1
2017-03-14 11:30:59 +00:00

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<?xml version="1.0" encoding="utf-8"?>
<!-- $Revision$ -->
<refentry xml:id="function.each" xmlns="http://docbook.org/ns/docbook">
<refnamediv>
<refname>each</refname>
<refpurpose>Return the current key and value pair from an array and advance the array cursor</refpurpose>
</refnamediv>
<refsynopsisdiv>
&warn.deprecated.function-7-2-0;
</refsynopsisdiv>
<refsect1 role="description">
&reftitle.description;
<methodsynopsis>
<type>array</type><methodname>each</methodname>
<methodparam><type>array</type><parameter role="reference">array</parameter></methodparam>
</methodsynopsis>
<para>
Return the current key and value pair from an array and advance the array
cursor.
</para>
<para>
After <function>each</function> has executed, the array cursor
will be left on the next element of the array, or past the last
element if it hits the end of the array. You have to use
<function>reset</function> if you want to traverse the array
again using each.
</para>
</refsect1>
<refsect1 role="parameters">
&reftitle.parameters;
<para>
<variablelist>
<varlistentry>
<term><parameter>array</parameter></term>
<listitem>
<para>
The input array.
</para>
</listitem>
</varlistentry>
</variablelist>
</para>
</refsect1>
<refsect1 role="returnvalues">
&reftitle.returnvalues;
<para>
Returns the current key and value pair from the array
<parameter>array</parameter>. This pair is returned in a four-element
array, with the keys <literal>0</literal>, <literal>1</literal>,
<literal>key</literal>, and <literal>value</literal>. Elements
<literal>0</literal> and <literal>key</literal> contain the key name of
the array element, and <literal>1</literal> and <literal>value</literal>
contain the data.
</para>
<para>
If the internal pointer for the array points past the end of the
array contents, <function>each</function> returns
&false;.
</para>
</refsect1>
<refsect1 role="examples">
&reftitle.examples;
<para>
<example>
<title><function>each</function> examples</title>
<programlisting role="php">
<![CDATA[
<?php
$foo = array("bob", "fred", "jussi", "jouni", "egon", "marliese");
$bar = each($foo);
print_r($bar);
?>
]]>
</programlisting>
<para>
<varname>$bar</varname> now contains the following key/value
pairs:
</para>
<screen>
<![CDATA[
Array
(
[1] => bob
[value] => bob
[0] => 0
[key] => 0
)
]]>
</screen>
</example>
</para>
<para>
<informalexample>
<programlisting role="php">
<![CDATA[
<?php
$foo = array("Robert" => "Bob", "Seppo" => "Sepi");
$bar = each($foo);
print_r($bar);
?>
]]>
</programlisting>
<para>
<varname>$bar</varname> now contains the following key/value
pairs:
</para>
<screen>
<![CDATA[
Array
(
[1] => Bob
[value] => Bob
[0] => Robert
[key] => Robert
)
]]>
</screen>
</informalexample>
</para>
<para>
<function>each</function> is typically used in conjunction with
<function>list</function> to traverse an array, here's an
example:
<example>
<title>Traversing an array with <function>each</function></title>
<programlisting role="php">
<![CDATA[
<?php
$fruit = array('a' => 'apple', 'b' => 'banana', 'c' => 'cranberry');
reset($fruit);
while (list($key, $val) = each($fruit)) {
echo "$key => $val\n";
}
?>
]]>
</programlisting>
&example.outputs;
<screen>
<![CDATA[
a => apple
b => banana
c => cranberry
]]>
</screen>
</example>
</para>
<caution>
<para>
Because assigning an array to another variable resets the original
array's pointer, our example above would cause an endless loop had we
assigned <varname>$fruit</varname> to another variable inside the
loop.
</para>
</caution>
<warning>
<para>
<function>each</function> will also accept objects, but may return unexpected
results. It's therefore not recommended to iterate though object properties
with <function>each</function>.
</para>
</warning>
</refsect1>
<refsect1 role="seealso">
&reftitle.seealso;
<para>
<simplelist>
<member><function>key</function></member>
<member><function>list</function></member>
<member><function>current</function></member>
<member><function>reset</function></member>
<member><function>next</function></member>
<member><function>prev</function></member>
<member>&foreach;</member>
<member><link linkend="language.oop5.iterations">Object Iteration</link></member>
</simplelist>
</para>
</refsect1>
</refentry>
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