mirror of
https://github.com/sigmasternchen/php-doc-en
synced 2025-03-19 18:38:55 +00:00
e4405eabb8
example to indicate that we're not trying to show every single option. Fixes doc bug #63383 (json_encode options bitmask). git-svn-id: https://svn.php.net/repository/phpdoc/en/trunk@328253 c90b9560-bf6c-de11-be94-00142212c4b1
318 lines
8.5 KiB
XML
318 lines
8.5 KiB
XML
<?xml version="1.0" encoding="utf-8"?>
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<!-- $Revision$ -->
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<refentry xml:id="function.json-encode" xmlns="http://docbook.org/ns/docbook">
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<refnamediv>
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<refname>json_encode</refname>
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<refpurpose>Returns the JSON representation of a value</refpurpose>
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</refnamediv>
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<refsect1 role="description">
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&reftitle.description;
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<methodsynopsis>
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<type>string</type><methodname>json_encode</methodname>
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<methodparam><type>mixed</type><parameter>value</parameter></methodparam>
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<methodparam choice="opt"><type>int</type><parameter>options</parameter><initializer>0</initializer></methodparam>
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</methodsynopsis>
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<para>
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Returns a string containing the JSON representation of
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<parameter>value</parameter>.
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</para>
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</refsect1>
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<refsect1 role="parameters">
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&reftitle.parameters;
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<para>
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<variablelist>
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<varlistentry>
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<term><parameter>value</parameter></term>
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<listitem>
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<para>
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The <parameter>value</parameter> being encoded. Can be any type except
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a <type>resource</type>.
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</para>
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<para>
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This function only works with UTF-8 encoded data.
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</para>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term><parameter>options</parameter></term>
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<listitem>
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<para>
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Bitmask consisting of <constant>JSON_HEX_QUOT</constant>,
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<constant>JSON_HEX_TAG</constant>,
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<constant>JSON_HEX_AMP</constant>,
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<constant>JSON_HEX_APOS</constant>,
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<constant>JSON_NUMERIC_CHECK</constant>,
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<constant>JSON_PRETTY_PRINT</constant>,
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<constant>JSON_UNESCAPED_SLASHES</constant>,
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<constant>JSON_FORCE_OBJECT</constant>,
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<constant>JSON_UNESCAPED_UNICODE</constant>. The behaviour of these
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constants is described on
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<link linkend="json.constants">the JSON constants page</link>.
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</para>
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</listitem>
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</varlistentry>
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</variablelist>
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</para>
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</refsect1>
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<refsect1 role="returnvalues">
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&reftitle.returnvalues;
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<para>
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Returns a JSON encoded <type>string</type> on success &return.falseforfailure;.
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</para>
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</refsect1>
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<refsect1 role="changelog">
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&reftitle.changelog;
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<para>
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<informaltable>
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<tgroup cols="2">
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<thead>
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<row>
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<entry>&Version;</entry>
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<entry>&Description;</entry>
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</row>
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</thead>
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<tbody>
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<row>
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<entry>5.4.0</entry>
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<entry>
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<constant>JSON_PRETTY_PRINT</constant>, <constant>JSON_UNESCAPED_SLASHES</constant>, and <constant>JSON_UNESCAPED_UNICODE</constant> <parameter>options</parameter> were added.
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</entry>
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</row>
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<row>
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<entry>5.3.3</entry>
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<entry>
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<constant>JSON_NUMERIC_CHECK</constant> <parameter>option</parameter> was added.
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</entry>
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</row>
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<row>
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<entry>5.3.0</entry>
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<entry>
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The <parameter>options</parameter> parameter was added.
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</entry>
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</row>
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</tbody>
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</tgroup>
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</informaltable>
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</para>
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</refsect1>
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<refsect1 role="examples">
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&reftitle.examples;
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<para>
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<example>
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<title>A <function>json_encode</function> example</title>
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<programlisting role="php">
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<![CDATA[
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<?php
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$arr = array('a' => 1, 'b' => 2, 'c' => 3, 'd' => 4, 'e' => 5);
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echo json_encode($arr);
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?>
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]]>
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</programlisting>
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&example.outputs;
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<screen>
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<![CDATA[
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{"a":1,"b":2,"c":3,"d":4,"e":5}
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]]>
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</screen>
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</example>
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<example>
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<title>
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A <function>json_encode</function> example showing some options in use
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</title>
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<programlisting role="php">
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<![CDATA[
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<?php
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$a = array('<foo>',"'bar'",'"baz"','&blong&', "\xc3\xa9");
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echo "Normal: ", json_encode($a), "\n";
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echo "Tags: ", json_encode($a, JSON_HEX_TAG), "\n";
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echo "Apos: ", json_encode($a, JSON_HEX_APOS), "\n";
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echo "Quot: ", json_encode($a, JSON_HEX_QUOT), "\n";
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echo "Amp: ", json_encode($a, JSON_HEX_AMP), "\n";
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echo "Unicode: ", json_encode($a, JSON_UNESCAPED_UNICODE), "\n";
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echo "All: ", json_encode($a, JSON_HEX_TAG | JSON_HEX_APOS | JSON_HEX_QUOT | JSON_HEX_AMP | JSON_UNESCAPED_UNICODE), "\n\n";
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$b = array();
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echo "Empty array output as array: ", json_encode($b), "\n";
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echo "Empty array output as object: ", json_encode($b, JSON_FORCE_OBJECT), "\n\n";
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$c = array(array(1,2,3));
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echo "Non-associative array output as array: ", json_encode($c), "\n";
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echo "Non-associative array output as object: ", json_encode($c, JSON_FORCE_OBJECT), "\n\n";
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$d = array('foo' => 'bar', 'baz' => 'long');
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echo "Associative array always output as object: ", json_encode($d), "\n";
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echo "Associative array always output as object: ", json_encode($d, JSON_FORCE_OBJECT), "\n\n";
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?>
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]]>
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</programlisting>
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&example.outputs;
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<screen>
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<![CDATA[
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Normal: ["<foo>","'bar'","\"baz\"","&blong&","\u00e9"]
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Tags: ["\u003Cfoo\u003E","'bar'","\"baz\"","&blong&","\u00e9"]
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Apos: ["<foo>","\u0027bar\u0027","\"baz\"","&blong&","\u00e9"]
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Quot: ["<foo>","'bar'","\u0022baz\u0022","&blong&","\u00e9"]
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Amp: ["<foo>","'bar'","\"baz\"","\u0026blong\u0026","\u00e9"]
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Unicode: ["<foo>","'bar'","\"baz\"","&blong&","é"]
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All: ["\u003Cfoo\u003E","\u0027bar\u0027","\u0022baz\u0022","\u0026blong\u0026","é"]
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Empty array output as array: []
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Empty array output as object: {}
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Non-associative array output as array: [[1,2,3]]
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Non-associative array output as object: {"0":{"0":1,"1":2,"2":3}}
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Associative array always output as object: {"foo":"bar","baz":"long"}
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Associative array always output as object: {"foo":"bar","baz":"long"}
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]]>
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</screen>
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</example>
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<example>
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<title>Sequential versus non-sequential array example</title>
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<programlisting role="php">
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<![CDATA[
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<?php
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echo "Sequential array".PHP_EOL;
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$sequential = array("foo", "bar", "baz", "blong");
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var_dump(
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$sequential,
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json_encode($sequential)
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);
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echo PHP_EOL."Non-sequential array".PHP_EOL;
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$nonsequential = array(1=>"foo", 2=>"bar", 3=>"baz", 4=>"blong");
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var_dump(
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$nonsequential,
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json_encode($nonsequential)
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);
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echo PHP_EOL."Sequential array with one key unset".PHP_EOL;
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unset($sequential[1]);
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var_dump(
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$sequential,
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json_encode($sequential)
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);
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?>
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]]>
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</programlisting>
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&example.outputs;
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<screen>
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<![CDATA[
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Sequential array
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array(4) {
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[0]=>
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string(3) "foo"
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[1]=>
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string(3) "bar"
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[2]=>
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string(3) "baz"
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[3]=>
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string(5) "blong"
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}
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string(27) "["foo","bar","baz","blong"]"
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Non-sequential array
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array(4) {
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[1]=>
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string(3) "foo"
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[2]=>
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string(3) "bar"
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[3]=>
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string(3) "baz"
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[4]=>
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string(5) "blong"
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}
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string(43) "{"1":"foo","2":"bar","3":"baz","4":"blong"}"
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Sequential array with one key unset
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array(3) {
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[0]=>
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string(3) "foo"
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[2]=>
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string(3) "baz"
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[3]=>
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string(5) "blong"
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}
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string(33) "{"0":"foo","2":"baz","3":"blong"}"
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]]>
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</screen>
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</example>
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</para>
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</refsect1>
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<refsect1 role="notes">
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&reftitle.notes;
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<note>
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<para>
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In the event of a failure to encode, <function>json_last_error</function>
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can be used to determine the exact nature of the error.
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</para>
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</note>
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<note>
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<para>
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When encoding an array, if the keys are not a continuous numeric
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sequence starting from 0, all keys are encoded as strings, and
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specified explicitly for each key-value pair.
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</para>
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</note>
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<note>
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<para>
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Like the reference JSON encoder, <function>json_encode</function> will
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generate JSON that is a simple value (that is, neither an object nor an
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array) if given a <type>string</type>, <type>integer</type>,
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<type>float</type> or <type>boolean</type> as an input
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<parameter>value</parameter>. While most decoders will accept these values
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as valid JSON, some may not, as the specification is ambiguous on this
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point.
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</para>
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<para>
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To summarise, always test that your JSON decoder can handle the output you
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generate from <function>json_encode</function>.
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</para>
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</note>
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</refsect1>
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<refsect1 role="seealso">
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&reftitle.seealso;
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<para>
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<simplelist>
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<member><interfacename>JsonSerializable</interfacename></member>
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<member><function>json_decode</function></member>
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<member><function>json_last_error</function></member>
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<member><function>serialize</function></member>
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</simplelist>
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</para>
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</refsect1>
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</refentry>
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<!-- Keep this comment at the end of the file
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Local variables:
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mode: sgml
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sgml-omittag:t
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sgml-shorttag:t
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sgml-minimize-attributes:nil
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sgml-always-quote-attributes:t
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sgml-indent-step:1
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sgml-indent-data:t
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indent-tabs-mode:nil
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sgml-parent-document:nil
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sgml-default-dtd-file:"~/.phpdoc/manual.ced"
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sgml-exposed-tags:nil
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sgml-local-catalogs:nil
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sgml-local-ecat-files:nil
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End:
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vim600: syn=xml fen fdm=syntax fdl=2 si
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vim: et tw=78 syn=sgml
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vi: ts=1 sw=1
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-->
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