Question

请参阅下面的示例以了解这个想法：

$arr = array
(
    0 => array (
        $this => 3,   // instead 0 => 3,
        'name' => 'three',
    ),
    1 => array (
        $this => 5,   // instead 0 => 5,
        'name' => 'five',
    ),
    2 => array (
        $this => 7,   // instead 0 => 7,
        'name' => 'seven',
    ),
);

对于每个索引都有一个二维数组。但是为了调用$ arr [0] [0]，转而调用$ arr [0]。这些虚构的想法与想要的结果相呼应。

echo $arr[0];           // printing 3
echo $arr[0]['name'];   // printing 'three'
echo $arr[0][0];        // printing 3 (not relevant)

有类似的东西吗？

Answer 1

在PHP 5中，您可以扩展ArrayObject以使其成为类似于数组的对象。你可以覆盖它的一些行为

-Xmx20480M
-XX:PermSize=128M
-XX:MaxPermSize=256M
-XX:+UseConcMarkSweepGC
-XX:+CMSClassUnloadingEnabled
-Xms20480M
-XX:NewSize=10240M
-XX:SurvivorRatio=4
-XX:+UseCompressedOops
-XX:CMSInitiatingOccupancyFraction=60
-XX:+UseStringCache
-XX:+UseFastAccessorMethods
-XX:ErrorFile=c:/hs_err.log
-XX:HeapDumpPath=c:/
-XX:+HeapDumpOnOutOfMemoryError
-Xrs

Answer 2

您正在尝试访问多维数组的元素

<?php
         $marks = array( 
            "m" => array
            (
               "physics" => 35,
               "maths" => 30,   
               "chemistry" => 39
            ),

            "q" => array
            (
               "physics" => 30,
               "maths" => 32,
               "chemistry" => 29
            ),

            "z" => array
            (
               "physics" => 31,
               "maths" => 22,
               "chemistry" => 39
            )
         );

         /* Accessing multi-dimensional array values */
         echo "Marks for m in physics : " ;
         echo $marks['m']['physics'] . "<br />"; 

         echo "Marks for q in maths : ";
         echo $marks['q']['maths'] . "<br />"; 

         echo "Marks for z in chemistry : " ;
         echo $marks['z']['chemistry'] . "<br />"; 
      ?>

这将产生

Marks for m in physics : 35
Marks for q in maths : 32
Marks for z in chemistry : 39

https://3v4l.org/bpL4i

现在你的问题是通过调用$ arr [0]来返回$ arr [0] [0]的值，因为@icecub说'然后这可以通过

来完成

reset（）函数用于将数组的内部指针移动到第一个元素。LINK

https://3v4l.org/Ide2L实施

只能返回值的多维数组的索引吗？

2 个答案: