Question

如何创建（在PHP中）和对象数组的数组？例如，说我有：

$arr[0] = array("eref_id" => "A001", "eref_child" => "A100", "level" => 1);
$arr[1] = array("eref_id" => "A002", "eref_child" => "A200", "level" => 2);
$arr[2] = array("eref_id" => "A003", "eref_child" => "A300", "level" => 3);
$arr[3] = array("eref_id" => "A003", "eref_child" => "A310", "level" => 3);

我想要一个新数组，其中＆＃34; arr＆＃34;是＆＃34; eref_id＆＃34;和＆＃34; eref_child＆＃34;但是数组的索引是＆＃34; level＆＃34;元件。所以基本上，

$newarr[1] would contain $arr[0]
$newarr[2] would contain $arr[1]
$newarr[3] would contain $arr[2]

和$arr[3]（因为两者都有＆＃34;等级＆＃34;为3）。

这将包含$arr[2]和$arr[3]的数组。

希望这是有道理的

Answer 1

您可以使用ouzo goodies

轻松完成

在php 5.4中：

$result = Arrays::toMap($arr, Functions::extract()['level']);

在php 5.3中：

$result = Arrays::toMap($arr, function($elem) { return $elem['level']; });

如果您有一个例如用户对象：

$cities = Arrays::map($users, Functions::extract()->getAddress('home')->city);

退房：http://ouzo.readthedocs.org/en/latest/utils/functions.html#extract

Answer 2

<?php
$arr[0] = array("eref_id" => "A001", "eref_child" => "A100", "level" => 1);
$arr[1] = array("eref_id" => "A002", "eref_child" => "A200", "level" => 2);
$arr[2] = array("eref_id" => "A003", "eref_child" => "A300", "level" => 3);
$arr[3] = array("eref_id" => "A003", "eref_child" => "A310", "level" => 3);

foreach($arr as $a){
    $newarr[$a['level']][] = $a;
}

echo '<pre>',print_r($newarr),'</pre>';

对象数组的索引数组

2 个答案: