array_add :

array_add function is used to add a key/value pair to the array.It will add only when there is no such key available in the existing array

Example:

$array = array('foo' => 'bar');

$array = array_add($array, 'key', 'value');

array_divide:

The array_divide function returns 2 arrays .First array will return the keys and second array will return the value of original array.

Example:

$array = array('foo' => 'bar');

list($keys, $values) = array_divide($array);

array_sort:

array_sort:

The array_sort function is used to sort the array from given array.

Example:

$array = array(
    array('name' => 'Jill'),
    array('name' => 'Barry'),
);

$array = array_values(array_sort($array, function($value)
{
    return $value['name'];
}));