Question

我想获取没有foreach的数组的索引。这是示例数组

$this->rci_db->select (" 
        $this->tbl_register.id,
        $this->tbl_register.cor,
        DATE_FORMAT($this->tbl_register.registerdate, '%d/%m/%Y') AS registerdate,
        $this->tbl_registrations.registration,
        $this->tbl_aircrafts.cn,
        $this->tbl_aircrafts.built,
        $this->tbl_manufacturers.manufacturer, 
        $this->tbl_models.type AS model,
        COUNT($this->tbl_images.imgid) AS count
        ");
    $this->rci_db->from("$this->tbl_register");
    $this->rci_db->join("$this->tbl_registrations", "$this->tbl_registrations.rid = $this->tbl_register.rid", 'left');
    $this->rci_db->join("$this->tbl_aircrafts", "$this->tbl_register.aid = $this->tbl_aircrafts.aid", 'left');
    $this->rci_db->join("$this->tbl_manufacturers", "$this->tbl_manufacturers.mid = $this->tbl_aircrafts.mid", 'left');
    $this->rci_db->join("$this->tbl_models", "$this->tbl_models.tid = $this->tbl_aircrafts.tid", 'left');
    $this->rci_db->join("$this->tbl_images", "$this->tbl_register.id = $this->tbl_images.id", 'left');

    $this->rci_db->where("$this->tbl_register.rid", $rid);

    $query = $this->rci_db->get();

    if ($query->num_rows() > 0)
    {
        return $query->result();
    }
    return false;

假设我的数据是 gcr_id = 21 ，通过与上述数组进行比较，它应该为我提供数组的索引 3

Answer 1

您可以结合使用array_search和array_column。 array_column返回具有键'gcr_id'的所有值，然后array_search返回对应于值21的键。

$array = array(
    array('gcr_distance' => 31.0, 'gcr_id' => 23),
    array('gcr_distance' => 28.0, 'gcr_id' => 22),
    array('gcr_distance' => 26.0, 'gcr_id' => 20),
    array('gcr_distance' => 110.0, 'gcr_id' => 21)
);

$key = array_search(21, array_column($array, 'gcr_id'));
echo $key;

输出：

受@Elementary评论的启发，我对此进行了一些基准测试。我发现，在100k条目数组中，当条目不在数组中时，array_search和array_column花费的时间是基于foreach的搜索的95％其中正在调用array_column。因此，似乎平均而言，基于foreach的搜索会更快。

获取多维数组的索引，值在php中

1 个答案: