Returns the average of two or more numbers.

Use array_sum() for all the values in $items and return the result divided by their count().

代码实现

function average(...$items)
{
  $count = count($items);

  return $count === 0 ? 0 : array_sum($items) / $count;
}

使用样例

average(1, 2, 3); // 2