调用我的对象及其功能

I am new to php and trying using Factory Method. I want to instantiate my class Shapes using 'build' function,such that when the class 'Circle' is instantiated its area and circumference is calculated and if the class 'Rectangle' is called ,its area and circumference is calculated and returned. This is what I have so far and what i want to achieve.This doesnt work and i am sure there is a better way of doing it!

$allmyshapes = Shapes::build($initData);
 foreach($allmyshapes as $value) { 
  if ($value =='Circle'){
   $x = new Circle();
   echo $x::area();
   echo $x::circumference();
}
 if ($value =='Rectangle'){
   $y = new Rectangle();
   echo $y::area();
   echo $y::circumference();

}

}

My Class:

class Shapes {
  public static function build($initData){

    }
    foreach($newlist as $value){
       if($value[0]=='Circle'){
          $shape1 =new Circle($value[1],$value[2]);
        }
       if($value[0]== 'Rectangle'){
         $shape2 =new Rectangle($value[1],$value[2]); 
        }

    }
     return array($shape1,$shape2);
  }

}

class Circle extends Shapes {
  public $radius;
  public $centre_point;
  public function __construct($radius, $centre_point) {
    $this->radius = $radius;
    $this->centre_point = $centre_point;
  }
  public function area(){
    return (pi() *$this->radius * $this->radius);
  }
  public function circumference(){
    return 2 * pi() *$this->radius;
  }

 }

class Rectangle extends Shapes {
  public $x;
  public $y;
  public function __construct($x, $y) {
    $this->x= $x;
    $this->y = $y;
  }
  public function area() {
    return $this->x * $this->y;
  }
  public function circumference() {
    return 2 * ($this->x+ $this->y);
  }

}

There's nothing wrong with your classes, it was how you were using them to output information:

class Shapes {
    public static function build($initData){
        //$initdata is a heredoc
        $newlist = explode("
", $initData);
        foreach($newlist as $key => $initData){
            $newlist[$key] = explode("\t", $initData);
        }
        foreach($newlist as $value){
            if($value[0] == 'Circle'){
                $shape1 = new Circle($value[1], $value[2]);
            }
            if($value[0] == 'Rectangle'){
                $shape2 = new Rectangle($value[1], $value[2]);
            }
        }
        return array($shape1, $shape2);
    }
}

class Circle extends Shapes {
    public $radius;
    public $centre_point;
    public function __construct($radius, $centre_point){
        $this->radius = $radius;
        $this->centre_point = $centre_point;
    }
    public function area(){
        return (pi() * $this->radius * $this->radius);
    }
    public function circumference(){
        return 2 * pi() * $this->radius;
    }
    public function draw(){
        return ( $this->radius.":".$this->centre_point);
    }
}

class Rectangle extends Shapes {
    public $x;
    public $y;
    public function __construct($x, $y){
        $this->x = $x;
        $this->y = $y;
    }
    public function area(){
        return $this->x * $this->y;
    }
    public function circumference(){
        return 2 * ($this->x + $this->y);
    }
}

$initData = <<<ENDINIT
Circle  5   2
Rectangle   5   10
Ellipse 10 10   4   5
ENDINIT;
$allmyshapes = Shapes::build($initData);
foreach($allmyshapes as $value){
    if(get_class($value) === 'Circle'){
        echo nl2br("**Circle**
Area: ".$value->area()."
Circumference: ".$value->circumference()."
");
    }
    if(get_class($value) === 'Rectangle'){
         echo nl2br("**Rectangle**
Area: ".$value->area()."
Circumference: ".$value->circumference()."
");
    }
}

I added 2 functions to your provided code, get_class() & nl2br(). the nl2br can be removed if you are using this in CLI format, but its main function was for output readability when using a web browser to view the output.

get_class() will solve your issue of trying to figure out what constructor was used in the creation of the object.