Php 在类构造函数中使用匿名函数并在方法中使用

我试图在构造函数中使用匿名函数，将其分配给公共变量，然后在方法中使用该变量

我的班级

class siteAnalytics {
    public $db_count;                                           // FUNCTION "$db_count" - CALLED FROM "FUNCTIONS.PHP"
    public $db_sum;                                             // FUNCTION "$db_sum" - CALLED FROM "FUNCTIONS.PHP"
    public $db_readAll;                                         // FUNCTION "$db_readAll" - CALLED FROM "FUNCTIONS.PHP"

    public function __construct($db_count, $db_sum, $db_readAll) {
        $this->db_count   = $db_count;
        $this->db_sum     = $db_sum;
        $this->db_readAll = $db_readAll;
    }

    public function siteData(){
        // CREATE "SITE DATA" ARRAY FROM QUERIES
        $SD_array = array(
            'U_active'       => $this->db_count("users", "*", "WHERE a_status='true'"),
        );
    }
}

$siteAnalytics = new siteAnalytics($db_count, $db_sum, $db_readAll);
print_r($siteAnalytics->siteData());

呼叫上课

class siteAnalytics {
    public $db_count;                                           // FUNCTION "$db_count" - CALLED FROM "FUNCTIONS.PHP"
    public $db_sum;                                             // FUNCTION "$db_sum" - CALLED FROM "FUNCTIONS.PHP"
    public $db_readAll;                                         // FUNCTION "$db_readAll" - CALLED FROM "FUNCTIONS.PHP"

    public function __construct($db_count, $db_sum, $db_readAll) {
        $this->db_count   = $db_count;
        $this->db_sum     = $db_sum;
        $this->db_readAll = $db_readAll;
    }

    public function siteData(){
        // CREATE "SITE DATA" ARRAY FROM QUERIES
        $SD_array = array(
            'U_active'       => $this->db_count("users", "*", "WHERE a_status='true'"),
        );
    }
}

$siteAnalytics = new siteAnalytics($db_count, $db_sum, $db_readAll);
print_r($siteAnalytics->siteData());

错误是什么？

未捕获错误：调用未定义的方法siteAnalytics:：db_count（）

我在调用

$this->db\u count

的数组中的

siteData（）

方法中得到错误

---

我知道我可以通过方法传递匿名函数，但为什么它在通过构造函数时不起作用。

您可以尝试将属性分配给局部变量，然后像调用函数一样调用它：

public function siteData(){
    $db_count = $this->db_count;
    // CREATE "SITE DATA" ARRAY FROM QUERIES
    $SD_array = array(
        'U_active'       => $db_count("users", "*", "WHERE a_status='true'"),
    );
}

更新： 您可以尝试用一对括号将属性括起来：

public function siteData(){
    // CREATE "SITE DATA" ARRAY FROM QUERIES
    $SD_array = array(
        'U_active'       => ($this->db_count)("users", "*", "WHERE a_status='true'"),
    );
}

---

您可以尝试将属性指定给局部变量，然后像调用函数一样调用它：

public function siteData(){
    $db_count = $this->db_count;
    // CREATE "SITE DATA" ARRAY FROM QUERIES
    $SD_array = array(
        'U_active'       => $db_count("users", "*", "WHERE a_status='true'"),
    );
}

更新： 您可以尝试用一对括号将属性括起来：

public function siteData(){
    // CREATE "SITE DATA" ARRAY FROM QUERIES
    $SD_array = array(
        'U_active'       => ($this->db_count)("users", "*", "WHERE a_status='true'"),
    );
}