array.xml

<?xml version="1.0" encoding="utf-8"?>
<!-- EN-Revision: 43d07782b514d0c7a8487f2c74063739f302df8d Maintainer: mowangjuanzi Status: ready -->
<sect1 xml:id="language.operators.array">
 <title>数组运算符</title>
 <titleabbrev>数组</titleabbrev>
 <table>
  <title>数组运算符</title>
  <tgroup cols="3">
   <thead>
    <row>
     <entry>例子</entry>
     <entry>名称</entry>
     <entry>结果</entry>
    </row>
   </thead>
   <tbody>
    <row>
     <entry>$a + $b</entry>
     <entry>联合</entry>
     <entry><varname>$a</varname> 和 <varname>$b</varname> 的联合。</entry>
    </row>
    <row>
     <entry>$a == $b</entry>
     <entry>相等</entry>
     <entry>如果 <varname>$a</varname> 和 <varname>$b</varname> 具有相同的键／值对则为 &true;。</entry>
    </row>
    <row>
     <entry>$a === $b</entry>
     <entry>全等</entry>
     <entry>如果 <varname>$a</varname> 和 <varname>$b</varname> 具有相同的键／值对并且顺序和类型都相同则为 &true;。</entry>
    </row>
    <row>
     <entry>$a != $b</entry>
     <entry>不等</entry>
     <entry>如果 <varname>$a</varname> 不等于 <varname>$b</varname> 则为 &true;。</entry>
    </row>
    <row>
     <entry>$a &lt;&gt; $b</entry>
     <entry>不等</entry>
     <entry>如果 <varname>$a</varname> 不等于 <varname>$b</varname> 则为 &true;。</entry>
    </row>
    <row>
     <entry>$a !== $b</entry>
     <entry>不全等</entry>
     <entry>如果 <varname>$a</varname> 不全等于 <varname>$b</varname> 则为 &true;。</entry>
    </row>
   </tbody>
  </tgroup>
 </table>
 <para>
  <literal>+</literal> 运算符把右边的数组元素附加到左边的数组后面，两个数组中都有的键名，则只用左边数组中的，右边的被忽略。
 </para>
 <para>
  <informalexample>
   <programlisting role="php">
<![CDATA[
<?php
$a = array("a" => "apple", "b" => "banana");
$b = array("a" => "pear", "b" => "strawberry", "c" => "cherry");

$c = $a + $b; // $a 和 $b 的并集
echo "Union of \$a and \$b: \n";
var_dump($c);

$c = $b + $a; // $b 和 $a 的并集
echo "Union of \$b and \$a: \n";
var_dump($c);

$a += $b; //  $a += $b 的并集是 $a 和 $b
echo "Union of \$a += \$b: \n";
var_dump($a);
?>
]]>
   </programlisting>
  </informalexample>
  执行后，此脚本会显示：
  <screen role="php">
<![CDATA[
Union of $a and $b:
array(3) {
  ["a"]=>
  string(5) "apple"
  ["b"]=>
  string(6) "banana"
  ["c"]=>
  string(6) "cherry"
}
Union of $b and $a:
array(3) {
  ["a"]=>
  string(4) "pear"
  ["b"]=>
  string(10) "strawberry"
  ["c"]=>
  string(6) "cherry"
}
Union of $a += $b:
array(3) {
  ["a"]=>
  string(5) "apple"
  ["b"]=>
  string(6) "banana"
  ["c"]=>
  string(6) "cherry"
}
]]>
  </screen>
 </para>
 <para>
  数组中的单元如果具有相同的键名和值则比较时相等。
 </para>
 <para>
  <example>
   <title>比较数组</title>
   <programlisting role="php">
<![CDATA[
<?php
$a = array("apple", "banana");
$b = array(1 => "banana", "0" => "apple");

var_dump($a == $b); // bool(true)
var_dump($a === $b); // bool(false)
?>
]]>
   </programlisting>
  </example>
 </para>

 <sect2 role="seealso">
  &reftitle.seealso;
  <para>
   <simplelist>
    <member><link linkend="language.types.array">数组类型</link></member>
    <member><link linkend="ref.array">数组函数</link></member>
   </simplelist>
  </para>
 </sect2>
</sect1>