PHP array_column() Function

In PHP, an array is a data structure that can hold an ordered list of values. It is a composite data type that allows you to store multiple values of the same data type under a single variable name.

Let us dive in.

Function Syntax

The following shows the syntax and definition for the array_function in PHP.

array_column(array $array, int|string|null $column_key, int|string|null $index_key = null): array

Function Parameters

The function accepts three main parameters:

1. array - this defines the multidimensional array or array of objects from which to pull the column values.
2. column_key - defines the column of values to return from the function. This can be an integer key of the column we wish to retrieve or a string key name for an associative array or property name.
3. index_key - this defines the column to use as the index/keys for the returned array.

Function Return Value

The function returns an array of values representing a single column from the input array.

Examples

Let us look at a basic example on how to use the array_column() function.

$customers = array(
    array('id' => 1, 'first_name' => 'John', 'last_name' => 'Doe'),
    array('id' => 2, 'first_name' => 'Jane', 'last_name' => 'Smith'),
    array('id' => 3, 'first_name' => 'Bob', 'last_name' => 'Johnson')
);

$first_names = array_column($customers, 'first_name');
print_r($first_names);

This should return an output as shown:

Array
(
    [0] => John
    [1] => Jane
    [2] => Bob
)

Example 2

We can also fetch the column of the last names from the recordset indexed by the id column:

$last_names = array_column($customers, 'last_name', 'id');
print_r($first_names);

The resulting output is as shown:

Array
(
    [0] => John
    [1] => Jane
    [2] => Bob
)

Conclusion

In this post, we discussed how we can use the array_column() function to fetch the values froma single column in a given input array.