在php中创建动态引用类型的对象

Question

In Javascript, I can refer to and use a constructor function dynamically:

function Circle() {
}

function Squere() {
}

var constructor = null; 

constructor = Circle;
var shape1 = new constructor(); 
console.log(shape1 instanceof Circle); // output: true

constructor = Squere;
var shape2 = new constructor(); 
console.log(shape2 instanceof Squere); // output: true

Is it possible and how can I do the same in php ? How can I take a class declaration in php and refer to and use it dynamically so the calling code does not know/care what it is creating ?

Answer 1

In PHP, you can't pass the class (or its constructor) itself, but its name:

class Circle { /* ... */ }
class Square { /* ... */ }

$classname = 'Circle';
$shape1 = new $classname();
// $shape1 is now a Circle