--TEST-- Test array_intersect_key() function : usage variation - Passing float indexed array --FILE-- '0', 10 => '10' , -10 => '-10'); $float_indx_array = array(0.0 => '0.0', 10.5 => '10.5' , -10.5 => '-10.5', 0.5 => '0.5'); echo "\n-- Testing array_intersect_key() function with float indexed array --\n"; var_dump( array_intersect_key($input_array, $float_indx_array) ); var_dump( array_intersect_key($float_indx_array,$input_array ) ); ?> --EXPECT-- *** Testing array_intersect_key() : usage variation *** -- Testing array_intersect_key() function with float indexed array -- array(3) { [0]=> string(1) "0" [10]=> string(2) "10" [-10]=> string(3) "-10" } array(3) { [0]=> string(3) "0.5" [10]=> string(4) "10.5" [-10]=> string(5) "-10.5" }