I have an array as follows:

我有一个数组如下:

$arr1 = array(
  0 => array(
    'name' => 'tom',
    'age' => 22
  ),
  1 => array(
    'name' => 'nick',
    'age' => 18
  )
);

However I want to create an array from it which consists of all the names, so it would become:

但是我想从它创建一个由所有名称组成的数组,因此它将成为:

$arr2 = array('tom', 'nick');

I have looked at array_filter(), but that would not work as this is a multi-dimensional array!

我看过array_filter(),但这不会起作用,因为这是一个多维数组!

Question

How can I create an array with the values of a specific key (name) from another multi-dimensional array?

如何使用来自另一个多维数组的特定键(名称)的值创建数组?

3 个解决方案

#1

Newer versions of PHP allow using array_map() with a function expression instead of a function name:

较新版本的PHP允许使用带有函数表达式而不是函数名的array_map():

$arr2 = array_map(function($person) {
    return $person['name'];
}, $arr1);

But if you are using a PHP < 5.3, it is much easier to use a simple loop, since array_map() would require to define a (probably global) function for this simple operation.

但是如果你使用的是PHP <5.3,那么使用一个简单的循环要容易得多,因为array_map()需要为这个简单的操作定义一个(可能是全局的)函数。

$arr2 = array();

foreach ($arr1 as $person) {
    $arr2[] = $person['name'];
}

// $arr2 now contains all names

#2

This can be done in still more simple way by using array_coulmn

这可以通过使用array_coulmn以更简单的方式完成

$arr2= array_column($arr1, 'name');

print_r($arr2); //Array ( [0] => tom [1] => nick )

array_column is used to get the columns of a sub-array.

array_column用于获取子数组的列。

#3

$array = array(0 => array('name' => 'tom', 'age' => 22), 1 => array('name' => 'nick', 'age' => 18));
foreach($array as $arr => $a){
    $names[] = $array[$arr]["name"];
}

print_r($names); //Array ( [0] => tom [1] => nick )

#1