Type hinting in PHP 7 - array of objects

Question

Maybe I missed something but is there any option to define that function should have argument or return for example array of User objects?

Consider the following cod

Answer 1

A fairly simple approach is to create your own array type which works with PHP's built-in functions such as foreach, count, unset, indexing, etc. Here is an example:

class DataRowCollection implements \ArrayAccess, \Iterator, \Countable
{
    private $rows = array();
    private $idx = 0;

    public function __construct()
    {
    }

    // ArrayAccess interface

    // Used when adding or updating an array value
    public function offsetSet($offset, $value)
    {
        if ($offset === null)
        {
            $this->rows[] = $value;
        }
        else
        {
            $this->rows[$offset] = $value;
        }
    }

    // Used when isset() is called
    public function offsetExists($offset)
    {
        return isset($this->rows[$offset]);
    }

    // Used when unset() is called
    public function offsetUnset($offset)
    {
        unset($this->rows[$offset]);
    }

    // Used to retrieve a value using indexing
    public function offsetGet($offset)
    {
        return $this->rows[$offset];
    }

    // Iterator interface

    public function rewind()
    {
        $this->idx = 0;
    }

    public function valid()
    {
        return $this->idx < count($this->rows);
    }

    public function current()
    {
        return $this->rows[$this->idx];
    }

    public function key()
    {
        return $this->idx;
    }

    public function next()
    {
        $this->idx++;
    }

    // Countable interface

    public function count()
    {
        return count($this->rows);
    }
}

Usage example:

$data = new DataRowCollection(); // = array();
$data[] = new DataRow("person");
$data[] = new DataRow("animal");

It works just like a traditional array, but it is typed like you wanted it to be. Very simple and effective.