(PHP 5 >= 5.5.0, PHP 7, PHP 8)
array_column — Return the values from a single column in the input array
$array, int|string|null $column_key, int|string|null $index_key = null): array
array_column() returns the values from a single column of
the array, identified by the
column_key. Optionally, an
index_key may be provided to index the values in the
returned array by the values from the index_key
column of the input array.
arrayA multi-dimensional array or an array of objects from which to pull a column of values from. If an array of objects is provided, then public properties can be directly pulled. In order for protected or private properties to be pulled, the class must implement both the __get() and __isset() magic methods.
column_key
The column of values to return. This value may be an integer key of the
column you wish to retrieve, or it may be a string key name for an
associative array or property name. It may also be null to return
complete arrays or objects (this is useful together with
index_key to reindex the array).
index_keyThe column to use as the index/keys for the returned array. This value may be the integer key of the column, or it may be the string key name. The value is cast as usual for array keys (however, prior to PHP 8.0.0, objects supporting conversion to string were also allowed).
Returns an array of values representing a single column from the input array.
| Version | Description |
|---|---|
| 8.0.0 |
Objects in columns indicated by index_key parameter
will no longer be cast to string and will now throw a TypeError instead.
|
Example #1 Get the column of first names from a recordset
<?php
// Array representing a possible record set returned from a database
$records = array(
array(
'id' => 2135,
'first_name' => 'John',
'last_name' => 'Doe',
),
array(
'id' => 3245,
'first_name' => 'Sally',
'last_name' => 'Smith',
),
array(
'id' => 5342,
'first_name' => 'Jane',
'last_name' => 'Jones',
),
array(
'id' => 5623,
'first_name' => 'Peter',
'last_name' => 'Doe',
)
);
$first_names = array_column($records, 'first_name');
print_r($first_names);
?>
The above example will output:
Array
(
[0] => John
[1] => Sally
[2] => Jane
[3] => Peter
)
Example #2 Get the column of last names from a recordset, indexed by the "id" column
<?php
// Using the $records array from Example #1
$last_names = array_column($records, 'last_name', 'id');
print_r($last_names);
?>
The above example will output:
Array
(
[2135] => Doe
[3245] => Smith
[5342] => Jones
[5623] => Doe
)
Example #3 Get the column of usernames from the public "username" property of an object
<?php
class User
{
public $username;
public function __construct(string $username)
{
$this->username = $username;
}
}
$users = [
new User('user 1'),
new User('user 2'),
new User('user 3'),
];
print_r(array_column($users, 'username'));
?>
The above example will output:
Array
(
[0] => user 1
[1] => user 2
[2] => user 3
)
Example #4 Get the column of names from the private "name" property of an object using the magic __get() method.
<?php
class Person
{
private $name;
public function __construct(string $name)
{
$this->name = $name;
}
public function __get($prop)
{
return $this->$prop;
}
public function __isset($prop) : bool
{
return isset($this->$prop);
}
}
$people = [
new Person('Fred'),
new Person('Jane'),
new Person('John'),
];
print_r(array_column($people, 'name'));
?>
The above example will output:
Array
(
[0] => Fred
[1] => Jane
[2] => John
)