archived-doc-zh/reference/array/functions/array-unique.xml

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<refentry xml:id="function.array-unique" xmlns="http://docbook.org/ns/docbook">
   <refnamediv>
    <refname>array_unique</refname>
    <refpurpose>移除数组中重复的值</refpurpose>
   </refnamediv>
 <refsect1 role="description">
  &reftitle.description;
     <methodsynopsis>
      <type>array</type><methodname>array_unique</methodname>
      <methodparam><type>array</type><parameter>array</parameter></methodparam>
    <methodparam choice="opt"><type>int</type><parameter>sort_flags</parameter><initializer>SORT_STRING</initializer></methodparam>
     </methodsynopsis>
    <para>
     <function>array_unique</function> 接受
     <parameter>array</parameter> 作为输入并返回没有重复值的新数组。
    </para>
    <para>
     注意键名保留不变。<function>array_unique</function>
     先将值作为字符串排序，然后对每个值只保留第一个遇到的键名，接着忽略所有后面的键名。这并不意味着在未排序的
     <parameter>array</parameter> 中同一个值的第一个出现的键名会被保留。
    </para>
    <note>
     <simpara>
      当且仅当
      <literal>(string) $elem1 === (string) $elem2</literal> 时两个单元被认为相同。就是说，当字符串的表达一样时。
     </simpara>
     <simpara>
      第一个单元将被保留。
     </simpara>
    </note>
   </refsect1>

 <refsect1 role="parameters">
  &reftitle.parameters;
  <para>
   <variablelist>
    <varlistentry>
     <term><parameter>array</parameter></term>
     <listitem>
      <para>
       输入的数组。
      </para>
     </listitem>
    </varlistentry>
    <varlistentry>
     <term><parameter>sort_flags</parameter></term>
     <listitem>
      <para>
       The optional second parameter <parameter>sort_flags</parameter>
       may be used to modify the sorting behavior using these values:
      </para>
      <para>
       Sorting type flags:
       <itemizedlist>
        <listitem>
         <simpara><constant>SORT_REGULAR</constant> - compare items normally
         (don't change types)</simpara>
        </listitem>
        <listitem>
         <simpara><constant>SORT_NUMERIC</constant> - compare items numerically</simpara>
        </listitem>
        <listitem>
         <simpara><constant>SORT_STRING</constant> - compare items as strings</simpara>
        </listitem>
        <listitem>
         <simpara><constant>SORT_LOCALE_STRING</constant> - compare items as
          strings, based on the current locale.
          <!--
          FIXME: PHP_6
          Before PHP 6, it uses the system locale, which can be changed using
          <function>setlocale</function>. Since PHP 6, you must use the
          <function>i18n_loc_set_default</function> function.
          -->
         </simpara>
        </listitem>
       </itemizedlist>
      </para>
     </listitem>
    </varlistentry>
   </variablelist>
  </para>
 </refsect1>

 <refsect1 role="returnvalues">
  &reftitle.returnvalues;
  <para>
   Returns the filtered array.
  </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>5.2.10</entry>
       <entry>
        Changed the default value of <parameter>sort_flags</parameter> back to
        <constant>SORT_STRING</constant>.
       </entry>
      </row>
      <row>
       <entry>5.2.9</entry>
       <entry>
        Added the optional <parameter>sort_flags</parameter> defaulting
        to <constant>SORT_REGULAR</constant>. Prior to 5.2.9, this function used to sort
        the array with <constant>SORT_STRING</constant> internally.
       </entry>
      </row>
     </tbody>
    </tgroup>
   </informaltable>
  </para>
 </refsect1>

 <refsect1 role="examples">
  &reftitle.examples;
  <para>
   <example>
    <title><function>array_unique</function> 例子</title>
    <programlisting role="php">
<![CDATA[
<?php
$input = array("a" => "green", "red", "b" => "green", "blue", "red");
$result = array_unique($input);
print_r($result);
?>
]]>
    </programlisting>
    &example.outputs;
    <screen role="php">
<![CDATA[
Array
(
    [a] => green
    [0] => red
    [1] => blue
)
]]>
    </screen>
   </example>
  </para>
  <para>
   <example>
    <title><function>array_unique</function> 和类型</title>
    <programlisting role="php">
<![CDATA[
<?php
$input = array(4, "4", "3", 4, 3, "3");
$result = array_unique($input);
var_dump($result);
?>
]]>
    </programlisting>
    &example.outputs;
    <screen role="php">
<![CDATA[
array(2) {
  [0] => int(4)
  [2] => string(1) "3"
}
]]>
    </screen>
   </example>
  </para>
 </refsect1>
 
 <refsect1 role="seealso">
  &reftitle.seealso;
  <para>
   <simplelist>
    <member><function>array_count_values</function></member>
   </simplelist>
  </para>
 </refsect1>

 <refsect1 role="notes">
  &reftitle.notes;
  <note>
   <simpara>
    Note that <function>array_unique</function> is not intended to 
    work on multi dimensional arrays.
   </simpara>
  </note>
 </refsect1>
  </refentry>

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