php - 多维数组到PHP中的单个数组

Question

我在 PHP 中工作，所以我有一个这样的数组，我希望过滤器从这个数组中获取 user_id 到另一个数组，如下所示。

Array
(
    [0] => Array
        (
            [user_id] => 66
            [distance] => 0
        )

    [1] => Array
        (
            [user_id] => 68
            [distance] => 0
        )

    [2] => Array
        (
            [user_id] => 81
            [distance] => 0
        )

    [3] => Array
        (
            [user_id] => 65
            [distance] => 0.00010218008081861118
        )

)

我想要一个这样的数组，

$user_id=array(66,68,81,65);

Answer 1

使用array_column()

Returns an array of values representing a single column from the input array.

<?php

$user_array = array(
                  0 => array('user_id' => 1, 'name' => 'Bob'),
                  1 => array('user_id' => 2, 'name' => 'John'),
                  2 => array('user_id' => 3, 'name' => 'Mary')
              );

$users = array_column($user_array, 'user_id');

print_r($users);

输出:

Array
(
   [0] => 1
   [1] => 2
   [2] => 3
)