$arr = [300, 600, 900, 1200]; $number = 920; $deltas = array_reduce( $arr, function($t, $v) use ($number) { $t[$v] = abs($v - $number); return $t; }, [] ); asort($deltas); echo array_keys($deltas)[0];
$arr = [300, 600, 900, 1200]; $number = 920; $deltas = array_reduce( $arr, function($t, $v) use ($number) { $t[$v] = abs($v - $number); return $t; }, [] ); asort($deltas); echo array_keys($deltas)[0];