将二维数组转化为一维数组

/**
     * @param $result 二维数组
     * @return array  将二维数组转换成一维数组
     *
     */
    public function arrForm($result){
        $arr = [];
        if(is_array($result)){
            foreach ($result as $key =>$value){
                foreach($value as $k => $v){
                    $arr[$k]=$v;
                }
            }
        }
        return $arr;
    }

例：二维数组

Array
(
    [0] => Array
        (
            [id] => 666
            [title] => 测试666
            [catid] => 2
            [inputtime] => 1551337927
        )
)

转化为

Array
(
    [id] => 666
    [title] => 测试666 
    [catid] => 2 
    [inputtime] => 1551337927
)