PHP5变量范围和类构造

Question

I'm having problems with accessing variables from my classes...

class getuser {
    public function __construct($id) {
        $userquery = "SELECT * FROM users WHERE id = ".$id."";
        $userresult = mysql_query($userquery);
        $this->user = array();
        $idx = 0;
        while($user = mysql_fetch_object($userresult)){
           $this->user[$idx] = $user;
           ++$idx;
        }
    }
}

I'm setting this class in a global 'classes' file, and later on I pass through a user id into the following script:

$u = new getuser($userid);

    foreach($u->user as $user){
        echo $user->username;
    }

I'm hoping that this will give me the name of the user but it's not, where am I going wrong?!

Thanks

Answer 1

please define your users member as public in your class like this

class getuser {
    public $user = null;
    //...
}

Answer 2

in order to access a class property, you have to declare it public or implement getters and setters (second solution is preferable)

class A {

  public $foo;

  //class methods
}

$a = new A();
$a->foo = 'whatever';

with getters and setters, one per property

class B {

  private $foo2;

  public function getFoo2() {
    return $this->foo2;
  }

  public function setFoo2($value) {
    $this->foo2 = $value;
  }

}

$b = new B();
$b->setFoo2('whatever');  
echo $b->getFoo2();

in your example:

class getuser {
    private $user;

    public function __construct($id) {
        $userquery = "SELECT * FROM users WHERE id = ".$id."";
        $userresult = mysql_query($userquery);
        $this->user = array();
        $idx = 0;
        while($user = mysql_fetch_object($userresult)){
           $this->user[$idx] = $user;
           ++$idx;
        }
    }

    /* returns the property value */
    public function getUser() {
      return $this->user;
    }

    /* sets the property value */
    public function setUser($value) {
      $this->user = $value;
    }

}


$u = new getuser($userid);
$users_list = $u->getUser();

    foreach($users_list as $user) {
        echo $user->username;
    }