1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222
|
<?xml version="1.0" encoding="utf-8"?>
<!-- $Revision$ -->
<refentry xml:id="function.array-slice" xmlns="http://docbook.org/ns/docbook">
<refnamediv>
<refname>array_slice</refname>
<refpurpose>Extract a slice of the array</refpurpose>
</refnamediv>
<refsect1 role="description">
&reftitle.description;
<methodsynopsis>
<type>array</type><methodname>array_slice</methodname>
<methodparam><type>array</type><parameter>array</parameter></methodparam>
<methodparam><type>int</type><parameter>offset</parameter></methodparam>
<methodparam choice="opt"><type class="union"><type>int</type><type>null</type></type><parameter>length</parameter><initializer>&null;</initializer></methodparam>
<methodparam choice="opt"><type>bool</type><parameter>preserve_keys</parameter><initializer>&false;</initializer></methodparam>
</methodsynopsis>
<para>
<function>array_slice</function> returns the sequence of elements
from the array <parameter>array</parameter> as specified by the
<parameter>offset</parameter> and <parameter>length</parameter>
parameters.
</para>
</refsect1>
<refsect1 role="parameters">
&reftitle.parameters;
<para>
<variablelist>
<varlistentry>
<term><parameter>array</parameter></term>
<listitem>
<para>
The input array.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><parameter>offset</parameter></term>
<listitem>
<para>
If <parameter>offset</parameter> is non-negative, the sequence will
start at that offset in the <parameter>array</parameter>.
</para>
<para>
If <parameter>offset</parameter> is negative, the sequence will
start that far from the end of the <parameter>array</parameter>.
</para>
<note>
<para>
The <parameter>offset</parameter> parameter denotes the position
in the array, not the key.
</para>
</note>
</listitem>
</varlistentry>
<varlistentry>
<term><parameter>length</parameter></term>
<listitem>
<para>
If <parameter>length</parameter> is given and is positive,
then the sequence will have up to that many elements in it.
</para>
<para>
If the array is shorter than the <parameter>length</parameter>,
then only the available array elements will be present.
</para>
<para>
If <parameter>length</parameter> is given and is negative then the
sequence will stop that many elements from the end of the array.
</para>
<para>
If it is omitted, then the sequence will have everything
from <parameter>offset</parameter> up until the end of the
<parameter>array</parameter>.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><parameter>preserve_keys</parameter></term>
<listitem>
<note>
<para>
<function>array_slice</function> will reorder and reset the
integer array indices by default. This behaviour can be changed
by setting <parameter>preserve_keys</parameter> to &true;.
String keys are always preserved, regardless of this parameter.
</para>
</note>
</listitem>
</varlistentry>
</variablelist>
</para>
</refsect1>
<refsect1 role="returnvalues">
&reftitle.returnvalues;
<para>
Returns the slice. If the offset is larger than the size of the array,
an empty array is returned.
</para>
</refsect1>
<refsect1 role="examples">
&reftitle.examples;
<para>
<example>
<title><function>array_slice</function> examples</title>
<programlisting role="php">
<![CDATA[
<?php
$input = array("a", "b", "c", "d", "e");
$output = array_slice($input, 2); // returns "c", "d", and "e"
$output = array_slice($input, -2, 1); // returns "d"
$output = array_slice($input, 0, 3); // returns "a", "b", and "c"
// note the differences in the array keys
print_r(array_slice($input, 2, -1));
print_r(array_slice($input, 2, -1, true));
?>
]]>
</programlisting>
&example.outputs;
<screen>
<![CDATA[
Array
(
[0] => c
[1] => d
)
Array
(
[2] => c
[3] => d
)
]]>
</screen>
</example>
</para>
<para>
<example>
<title><function>array_slice</function> and one-based array</title>
<programlisting role="php">
<![CDATA[
<?php
$input = array(1 => "a", "b", "c", "d", "e");
print_r(array_slice($input, 1, 2));
?>
]]>
</programlisting>
&example.outputs;
<screen>
<![CDATA[
Array
(
[0] => b
[1] => c
)
]]>
</screen>
</example>
</para>
<para>
<example>
<title><function>array_slice</function> and array with mixed keys</title>
<programlisting role="php">
<![CDATA[
<?php
$ar = array('a'=>'apple', 'b'=>'banana', '42'=>'pear', 'd'=>'orange');
print_r(array_slice($ar, 0, 3));
print_r(array_slice($ar, 0, 3, true));
?>
]]>
</programlisting>
&example.outputs;
<screen>
<![CDATA[
Array
(
[a] => apple
[b] => banana
[0] => pear
)
Array
(
[a] => apple
[b] => banana
[42] => pear
)
]]>
</screen>
</example>
</para>
</refsect1>
<refsect1 role="seealso">
&reftitle.seealso;
<para>
<simplelist>
<member><function>array_chunk</function></member>
<member><function>array_splice</function></member>
<member><function>unset</function></member>
</simplelist>
</para>
</refsect1>
</refentry>
<!-- Keep this comment at the end of the file
Local variables:
mode: sgml
sgml-omittag:t
sgml-shorttag:t
sgml-minimize-attributes:nil
sgml-always-quote-attributes:t
sgml-indent-step:1
sgml-indent-data:t
indent-tabs-mode:nil
sgml-parent-document:nil
sgml-default-dtd-file:"~/.phpdoc/manual.ced"
sgml-exposed-tags:nil
sgml-local-catalogs:nil
sgml-local-ecat-files:nil
End:
vim600: syn=xml fen fdm=syntax fdl=2 si
vim: et tw=78 syn=sgml
vi: ts=1 sw=1
-->
|