class intercept_demo{
    private $xingming = "";
    private $age = 10;
  
    // 若訪問一個未定義的屬性，則將調用get{$property}對應的方法
    function __get($property){
        $method = "get{$property}";
        if (method_exists($this, $method)){
            return $this->$method();
        }
    }

 

    // 若給一個未定義的屬性設置值，則將調用set{$property}對應的方法
    function __set($property, $value){
        $method = "set{$property}";
        if (method_exists($this, $method)){
            return $this->$method($value);
        }  
    }
  
    // 若用戶對未定義的屬性調用isset方法，
    function __isset($property){
        $method = "isset{$property}";
        if (method_exists($this, $method)){
            return $this->$method();
        }
    }
  
    // 若用戶對未定義的屬性調用unset方法，
    // 則認為調用對應的unset{$property}方法
    function __unset($property){
        $method = "unset{$property}";
        if (method_exists($this, $method)){
            return $this->$method();
        }
    }
  
    function __call($method, $arg_array){
        if (substr($method,0,3)=="get"){
            $property = substr($method,3);
            $property = strtolower(substr($property,0,1)).substr($property,1);
            return $this->$property;
        }
    }
  
    function testIsset(){
        return isset($this->Name);
    }
  
    function getName(){
        return $this->xingming;
    }
  
    function setName($value){
        $this->xingming = $value;
    }
  
    function issetName(){
        return !is_null($this->xingming);
    }
  
    function unsetName(){
        $this->xingming = NULL;
    }
}

$intercept = new intercept_demo();
echo "設置屬性Name為Li";
$intercept->Name = "Li";
echo "\$intercept->Name={$intercept->Name}";
echo "isset(Name)={$intercept->testIsset()}";
echo "";
echo "清空屬性Name值";
unset($intercept->Name);
echo "\$intercept->Name={$intercept->Name}";
echo "";
echo "調用未定義的getAge函數";
echo "age={$intercept->getAge()}";