Question

我现在正在学习面向对象的php，我遇到了一个名为__toString（）的魔术方法的问题。

没有要求该功能。它与其他神奇功能相似吗？

如果将它用于我的班级，那么它是否将所有对象都转换为字符串？

代码 -

class MyClass
{
  public $prop1 = "I'm a class property!";

  public function __construct()
  {
      echo 'The class "', __CLASS__, '" was initiated!<br />';
  }

  public function __destruct()
  {
      echo 'The class "', __CLASS__, '" was destroyed.<br />';
  }

  public function __toString()
  {
      echo "Using the toString method: ";
      return $this->getProperty();
  }

  public function setProperty($newval)
  {
      $this->prop1 = $newval;
  }

  public function getProperty()
  {
      return $this->prop1 . "<br />";
  }
}

// Create a new object
$obj = new MyClass;

// Output the object as a string
echo $obj;

// Destroy the object
unset($obj);

// Output a message at the end of the file
echo "End of file.<br />";

?>

输出 -

The class "MyClass" was initiated! Using the toString method: I'm a class property! The class "MyClass" was destroyed. End of file.

Answer 1

当该类的对象被用作字符串时，将调用magic __toString方法：

class Something {
    private $whatever;
    public function __construct($whatever) {
        $this->whatever = $whatever;
    }
    public function __toString() {
        return $this->whatever;
    }
}

$obj = new Something("Whatever here!");
echo "Object is $obj"; // Object is Whatever here!

请参阅 The Docs 。

无法理解__toString（）函数OOP PHP

1 个答案: