如何操作php数组[重复]答案

【问题标题】：How to manipulate php arrays [duplicate]如何操作php数组[重复]
【发布时间】：2016-03-20 22:55:57
【问题描述】：

如何操作 php 数组。我在下面有一个 $data 变量。

$data = Array
(
 [0] => Array
    (
        [id] => 1
        [capacity] => 900
        [category] => users
    )

 [1] => Array
    (
        [id] => 2
        [capacity] => 300
        [category] => users
    )
 [2] => Array
    (
        [id] => 3
        [capacity] => 900
        [category] => students
    )
 [3] => Array
    (
        [id] => 4
        [capacity] => 300
        [category] => students
    )
)

现在我想将数据与下面的相同类别进行分组。 .我对php不是很熟悉。有人可以帮助我如何实现这一目标。我应该使用什么功能。谢谢

Array
(
[users] => Array
    (
        [0] => Array
            (
              [id] => 1
              [capacity] => 900
              [category] => users
            )

        [1] => Array
            (
              [id] => 2
              [capacity] => 300
              [category] => users
            )
    ),
[students] => Array
    (
        [0] => Array
            (
              [id] => 1
              [capacity] => 900
              [category] => students
            )

        [1] => Array
            (
              [id] => 2
              [capacity] => 300
              [category] => students
            )
    )
)

【问题讨论】：

foreach ($data as $array) { $output[$array['category']][] = $array; } print_r($output); 应该可以解决问题。
如果你使用var_export()而不是var_dump()来输出你的数组会更好，因为人们可以在他们的代码示例中重用输出。

标签： php

【解决方案1】：

只需遍历数组并根据category 字段的内容将其添加到新数组中：

$new = array();
foreach ($data as $val) {
    $new[$val['category']][] = $val;
}

【讨论】：

【解决方案2】：

这符合您的要求

<?php

$data = array(
    0 => array (
        "id" => 1,
        "capacity" => 900,
        "category" => "users"
    ),
    1 => array (
        "id" => 2,
        "capacity" => 300,
        "category" => "users"
    ),
    2 => array (
        "id" => 3,
        "capacity" => 900,
        "category" => "students"
    ),
    3 => array (
        "id" => 4,
        "capacity" => 300,
        "category" => "students"
    )
);

$groups = array();

foreach ($data as $i) {
  if ($i['category'] === "students") {
    $groups['students'][] = $i;
  }
  else if ($i['category'] === "users") {
    $groups['users'][] = $i;
  }
}

echo "<pre>", print_r($groups), "</pre>";

这是一个有效的演示 - http://codepad.viper-7.com/G4Br28

【讨论】：