Question

i have two arrays which keys are book id( 61, 78 ,…etc)

(1) book_width
     (
        [61] => 8.3
        [72] => 8286.1
        [78] => 6.4
        [100] => 8407.0
        [102] => 0.7
     )

---

(2) book_height
   (
    [61] => 9.00
    [72] => 150
    [78] => 8.00
    [100] => 150
    [102] => 3.00
  )

now i want an array which contain those books id’s which their height is greater than or equal to their width

means i need an array mention below

(2) book_dimension
       (     
 /*book id*/ [78] => 8.00 //along their height or width(anyone)
             [102] => 3.00
      )



 or only book id in a new array
    (2) book_dimension
           (     
            [0] => 78
            [1] => 102
      )

Answer 1

I believe this should do it:

function compare_dimensions( $width, $height )
{
 return $height < $width;
}

$result = array_uintersect_assoc( $array_width, $array_height, 'compare_dimensions' );

var_dump( $result );

EDIT:
Oops: Comparing should be the other way around. (changed >= to < )

documentation: http://docs.php.net/array_uintersect_assoc