Php 如何从一个类函数调用变量到另一个类函数_Php_Oop_Variables_Scope

Php 如何从一个类函数调用变量到另一个类函数

php oop variables

Php 如何从一个类函数调用变量到另一个类函数,php,oop,variables,scope,Php,Oop,Variables,Scope,我是php oop新手我有两个文件这是我的代码 1）info.php public $bd, $db1; class Connection { function connect() { $this->db = 'hello world'; $this->db1 = 'hi' } } class Connection { // these two variable should be declared within the

我是php oop新手

我有两个文件这是我的代码

1）info.php

public $bd, $db1;    
class Connection {  
  function connect() {  
    $this->db = 'hello world';  
    $this->db1 = 'hi'  
  }  
}

class Connection {
   // these two variable should be declared within the class.
   protected $db; // to be able to access these variables from a diff class
   protected $db1; // either their scope should be "protected" or define a getter method.

   public function __construct() {
      $this->connect();
   }

   private function connect() {
       $this->db = 'hello world';
       $this->db1 = 'hi';
   }
}

require_once 'info.php';

// you are accessing the Connection class in static scope
// which is not the case here.
class prdinfo extends Connection {
   public function __construct() {
       // initialize the parent class
       // which in turn sets the variables.
       parent::__construct();
   }

   public function productId() {
        echo $this->db;
        echo $this->db1;
   }
}


$prd = new prdinfo ();
$prd->productId ();

2）prd.php

require_once 'info.php'
class prdinfo {  
  function productId() {  
    echo Connection::connect()->$bd;  
    echo Connection::connect()->$db1;   
  }  
$prd = new prdinfo ();  
$prd->productId ();

如何在第二类中回显我的var我已经尝试过这种方法，但没有得到正确的输出

谢谢

应该是这样的

info.php

public $bd, $db1;    
class Connection {  
  function connect() {  
    $this->db = 'hello world';  
    $this->db1 = 'hi'  
  }  
}

class Connection {
   // these two variable should be declared within the class.
   protected $db; // to be able to access these variables from a diff class
   protected $db1; // either their scope should be "protected" or define a getter method.

   public function __construct() {
      $this->connect();
   }

   private function connect() {
       $this->db = 'hello world';
       $this->db1 = 'hi';
   }
}

require_once 'info.php';

// you are accessing the Connection class in static scope
// which is not the case here.
class prdinfo extends Connection {
   public function __construct() {
       // initialize the parent class
       // which in turn sets the variables.
       parent::__construct();
   }

   public function productId() {
        echo $this->db;
        echo $this->db1;
   }
}


$prd = new prdinfo ();
$prd->productId ();

prd.php

public $bd, $db1;    
class Connection {  
  function connect() {  
    $this->db = 'hello world';  
    $this->db1 = 'hi'  
  }  
}

class Connection {
   // these two variable should be declared within the class.
   protected $db; // to be able to access these variables from a diff class
   protected $db1; // either their scope should be "protected" or define a getter method.

   public function __construct() {
      $this->connect();
   }

   private function connect() {
       $this->db = 'hello world';
       $this->db1 = 'hi';
   }
}

require_once 'info.php';

// you are accessing the Connection class in static scope
// which is not the case here.
class prdinfo extends Connection {
   public function __construct() {
       // initialize the parent class
       // which in turn sets the variables.
       parent::__construct();
   }

   public function productId() {
        echo $this->db;
        echo $this->db1;
   }
}


$prd = new prdinfo ();
$prd->productId ();

这是一个基本的演示。根据您的需要进行修改。更多信息-

应该是这样的

info.php

public $bd, $db1;    
class Connection {  
  function connect() {  
    $this->db = 'hello world';  
    $this->db1 = 'hi'  
  }  
}

class Connection {
   // these two variable should be declared within the class.
   protected $db; // to be able to access these variables from a diff class
   protected $db1; // either their scope should be "protected" or define a getter method.

   public function __construct() {
      $this->connect();
   }

   private function connect() {
       $this->db = 'hello world';
       $this->db1 = 'hi';
   }
}

require_once 'info.php';

// you are accessing the Connection class in static scope
// which is not the case here.
class prdinfo extends Connection {
   public function __construct() {
       // initialize the parent class
       // which in turn sets the variables.
       parent::__construct();
   }

   public function productId() {
        echo $this->db;
        echo $this->db1;
   }
}


$prd = new prdinfo ();
$prd->productId ();

prd.php

public $bd, $db1;    
class Connection {  
  function connect() {  
    $this->db = 'hello world';  
    $this->db1 = 'hi'  
  }  
}

class Connection {
   // these two variable should be declared within the class.
   protected $db; // to be able to access these variables from a diff class
   protected $db1; // either their scope should be "protected" or define a getter method.

   public function __construct() {
      $this->connect();
   }

   private function connect() {
       $this->db = 'hello world';
       $this->db1 = 'hi';
   }
}

require_once 'info.php';

// you are accessing the Connection class in static scope
// which is not the case here.
class prdinfo extends Connection {
   public function __construct() {
       // initialize the parent class
       // which in turn sets the variables.
       parent::__construct();
   }

   public function productId() {
        echo $this->db;
        echo $this->db1;
   }
}


$prd = new prdinfo ();
$prd->productId ();

这是一个基本的演示。根据您的需要进行修改。更多信息-

应该是这样的

info.php

public $bd, $db1;    
class Connection {  
  function connect() {  
    $this->db = 'hello world';  
    $this->db1 = 'hi'  
  }  
}

class Connection {
   // these two variable should be declared within the class.
   protected $db; // to be able to access these variables from a diff class
   protected $db1; // either their scope should be "protected" or define a getter method.

   public function __construct() {
      $this->connect();
   }

   private function connect() {
       $this->db = 'hello world';
       $this->db1 = 'hi';
   }
}

require_once 'info.php';

// you are accessing the Connection class in static scope
// which is not the case here.
class prdinfo extends Connection {
   public function __construct() {
       // initialize the parent class
       // which in turn sets the variables.
       parent::__construct();
   }

   public function productId() {
        echo $this->db;
        echo $this->db1;
   }
}


$prd = new prdinfo ();
$prd->productId ();

prd.php

public $bd, $db1;    
class Connection {  
  function connect() {  
    $this->db = 'hello world';  
    $this->db1 = 'hi'  
  }  
}

class Connection {
   // these two variable should be declared within the class.
   protected $db; // to be able to access these variables from a diff class
   protected $db1; // either their scope should be "protected" or define a getter method.

   public function __construct() {
      $this->connect();
   }

   private function connect() {
       $this->db = 'hello world';
       $this->db1 = 'hi';
   }
}

require_once 'info.php';

// you are accessing the Connection class in static scope
// which is not the case here.
class prdinfo extends Connection {
   public function __construct() {
       // initialize the parent class
       // which in turn sets the variables.
       parent::__construct();
   }

   public function productId() {
        echo $this->db;
        echo $this->db1;
   }
}


$prd = new prdinfo ();
$prd->productId ();

这是一个基本的演示。根据您的需要进行修改。更多信息-

应该是这样的

info.php

public $bd, $db1;    
class Connection {  
  function connect() {  
    $this->db = 'hello world';  
    $this->db1 = 'hi'  
  }  
}

class Connection {
   // these two variable should be declared within the class.
   protected $db; // to be able to access these variables from a diff class
   protected $db1; // either their scope should be "protected" or define a getter method.

   public function __construct() {
      $this->connect();
   }

   private function connect() {
       $this->db = 'hello world';
       $this->db1 = 'hi';
   }
}

require_once 'info.php';

// you are accessing the Connection class in static scope
// which is not the case here.
class prdinfo extends Connection {
   public function __construct() {
       // initialize the parent class
       // which in turn sets the variables.
       parent::__construct();
   }

   public function productId() {
        echo $this->db;
        echo $this->db1;
   }
}


$prd = new prdinfo ();
$prd->productId ();

prd.php

public $bd, $db1;    
class Connection {  
  function connect() {  
    $this->db = 'hello world';  
    $this->db1 = 'hi'  
  }  
}

class Connection {
   // these two variable should be declared within the class.
   protected $db; // to be able to access these variables from a diff class
   protected $db1; // either their scope should be "protected" or define a getter method.

   public function __construct() {
      $this->connect();
   }

   private function connect() {
       $this->db = 'hello world';
       $this->db1 = 'hi';
   }
}

require_once 'info.php';

// you are accessing the Connection class in static scope
// which is not the case here.
class prdinfo extends Connection {
   public function __construct() {
       // initialize the parent class
       // which in turn sets the variables.
       parent::__construct();
   }

   public function productId() {
        echo $this->db;
        echo $this->db1;
   }
}


$prd = new prdinfo ();
$prd->productId ();

这是一个基本的演示。根据您的需要进行修改。更多信息-

首先，这两个类都不是有效的类声明。是否希望productId方法是静态的？第一步，需要在类内声明公共变量。然后使用extends扩展第二个类中的第一个类以访问基类变量您应该首先学习oop，因为您不知道它是什么以及它的用途，所以我们无法帮助您。这两个类都不是有效的类声明。首先，您希望productId方法是静态的吗？第一步，您需要声明public类中的变量。然后使用extends扩展第二个类中的第一个类以访问基类变量您应该首先学习oop，因为您不知道它是什么以及它的用途，所以我们无法帮助您。这两个类都不是有效的类声明。首先，您希望productId方法是静态的吗？第一步，您需要声明public类中的变量。然后使用extends扩展第二个类中的第一个类以访问基类变量您应该首先学习oop，因为您不知道它是什么以及它的用途，所以我们无法帮助您。这两个类都不是有效的类声明。首先，您希望productId方法是静态的吗？第一步，您需要声明public类中的变量。然后使用extends在第二个类中扩展第一个类以访问基类变量您应该先学习oop，因为您不知道它是什么，它的作用是什么，所以我们无法帮助您。可能有助于提及他们所犯的错误，其中有许多错误和

echo$this->$db应该是echo$this->db抓得好，@AmalMurali。已纠正。可能有助于提及他们所犯的错误，其中一些错误和echo$this->$db应该是echo$this->db抓得好，@AmalMurali。已纠正。可能有助于提及他们所犯的错误，其中一些错误和echo$this->$db应该是echo$this->db抓得好，@AmalMurali。已纠正。可能有助于提及他们所犯的错误，其中一些错误和echo$this->$db应该是echo$this->db抓得好，@AmalMurali。纠正了。