Values are returned by using the optional return statement. Any
type may be returned, including lists and objects. This causes the
function to end its execution immediately and pass control back to
the line from which it was called. See return()
for more information.
Example 17-11. Use of return()
return $num * $num;
echo square(4); // outputs '16'.
You can't return multiple values from a function, but similar
results can be obtained by returning a list.
Example 17-12. Returning an array to get multiple values
return array (0, 1, 2);
list ($zero, $one, $two) = small_numbers();
To return a reference from a function, you have to use
the reference operator & in both the function declaration and
when assigning the returned value to a variable:
Example 17-13. Returning a reference from a function
$newref =& returns_reference();
For more information on references, please check out References Explained.