src/Database/Builder.php
public function dropdown($column, $key = null)
    {
        $key = !is_null($key) ? $key : $this->model->getKeyName();

        return $this->lists($column, $key);
    }
public function dropdown($column, $key = null)
    {
        $key = !is_null($key) ? $key : $this->model->getKeyName();

        return $this->lists($column, $key);
    }
Get an array with the values of a given column.

@param  string $column
@param  string|null $key

@return \Illuminate\Support\Collection