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
|
<?xml version="1.0" encoding="utf-8"?>
<!-- $Revision$ -->
<refentry xml:id="function.print-r" xmlns="http://docbook.org/ns/docbook">
<refnamediv>
<refname>print_r</refname>
<refpurpose>
Prints human-readable information about a variable
</refpurpose>
</refnamediv>
<refsect1 role="description">
&reftitle.description;
<methodsynopsis>
<type class="union"><type>string</type><type>true</type></type><methodname>print_r</methodname>
<methodparam><type>mixed</type><parameter>value</parameter></methodparam>
<methodparam choice="opt"><type>bool</type><parameter>return</parameter><initializer>&false;</initializer></methodparam>
</methodsynopsis>
<para>
<function>print_r</function> displays information about a variable
in a way that's readable by humans.
</para>
<para>
<function>print_r</function>, <function>var_dump</function> and
<function>var_export</function> will
also show protected and private properties of objects.
Static class members will not be shown.
</para>
</refsect1>
<refsect1 role="parameters">
&reftitle.parameters;
<para>
<variablelist>
<varlistentry>
<term><parameter>value</parameter></term>
<listitem>
<para>
The expression to be printed.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><parameter>return</parameter></term>
<listitem>
<para>
If you would like to capture the output of <function>print_r</function>,
use the <parameter>return</parameter> parameter. When this parameter is set
to &true;, <function>print_r</function> will return the information rather than print it.
</para>
</listitem>
</varlistentry>
</variablelist>
</para>
</refsect1>
<refsect1 role="returnvalues">
&reftitle.returnvalues;
<para>
If given a <type>string</type>, <type>int</type> or <type>float</type>,
the value itself will be printed. If given an <type>array</type>, values
will be presented in a format that shows keys and elements. Similar
notation is used for <type>object</type>s.
</para>
<para>
When the <parameter>return</parameter> parameter is &true;, this function
will return a <type>string</type>. Otherwise, the return value is &true;.
</para>
</refsect1>
<refsect1 role="changelog">
&reftitle.changelog;
<para>
<informaltable>
<tgroup cols="2">
<thead>
<row>
<entry>&Version;</entry>
<entry>&Description;</entry>
</row>
</thead>
<tbody>
<row>
<entry>8.4.0</entry>
<entry>
Return type changed from <type class="union"><type>string</type><type>bool</type></type> to <type class="union"><type>string</type><type>true</type></type>.
</entry>
</row>
</tbody>
</tgroup>
</informaltable>
</para>
</refsect1>
<refsect1 role="examples">
&reftitle.examples;
<para>
<example>
<title><function>print_r</function> example</title>
<programlisting role="php">
<![CDATA[
<pre>
<?php
$a = array ('a' => 'apple', 'b' => 'banana', 'c' => array ('x', 'y', 'z'));
print_r ($a);
?>
</pre>
]]>
</programlisting>
&example.outputs;
<screen>
<![CDATA[
<pre>
Array
(
[a] => apple
[b] => banana
[c] => Array
(
[0] => x
[1] => y
[2] => z
)
)
</pre>
]]>
</screen>
</example>
</para>
<para>
<example>
<title><parameter>return</parameter> parameter example</title>
<programlisting role="php">
<![CDATA[
<?php
$b = array ('m' => 'monkey', 'foo' => 'bar', 'x' => array ('x', 'y', 'z'));
$results = print_r($b, true); // $results now contains output from print_r
?>
]]>
</programlisting>
</example>
</para>
</refsect1>
<refsect1 role="notes">
&reftitle.notes;
¬e.uses-ob-php70;
</refsect1>
<refsect1 role="seealso">
&reftitle.seealso;
<para>
<simplelist>
<member><function>ob_start</function></member>
<member><function>var_dump</function></member>
<member><function>var_export</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
-->
|