Is there a function to extract a 'column' from an array in PHP?

Question

I have an array of arrays, with the following structure :

array(array(\'page\' => \'page1\', \'name\' => \'pagename1\')
      array(\'page\' => \'pa         


        

Answer 1

Just to extend on some of the answers here, as of PHP 5.5, array_column is what you want.

It actually has a few possible uses.

Using the sample array below, here are the different ways to use array_column.

$a = array(
    array('id' => '1', 'name' => 'Joe'),
    array('id' => '2', 'name' => 'Jane')
);

Retrieving a single column as the array

$b = array_column($a, 'name');

Would give you. Notice the auto keys starting from 0, as per a normal array.

$b[0] = 'Joe';
$b[1] = 'Jane';

Retrieving the full array with a column as the index.

$c = array_column($a, NULL, 'id');

Would result in the following.

$c[1] = array('id' => '1', 'name' => 'Joe');
$c[2] = array('id' => '2', 'name' => 'Jane');

Notice how the column I selected as the third parameter becomes the key for each item and I get the full array by setting the second parameter to null.

Of course, the final usage is to set both the 2nd and 3rd params.

$d = array_column($a, 'name', 'id');

Would give you the following.

$d[1] = 'Joe';
$d[2] = 'Jane';

I personally use the full 3 params for creating select option lists. If I have a table with my options, I query the table and get the result and pass it into this to get a list with the key as the value and the label. This is a brilliant way for building info sets that need to intersect by the index as well.