Question

is it possible to do something like this in PHP 5.2.1?

abstract class Test
{
  public function __construct()
  {
     if (function_exists('init')):
        $this->init();
  }
}

If i try this, the function on the subclass is not called?

Answer 1

You can use method_exists to see if an object has a method with a given name. However, this doesn’t let you test what arguments the method takes. Since you’re defining an abstract class, simply make the desired method an abstract method.

abstract class Test {
    public function __construct() {
        $this->init();
    }
    abstract protected function init();
}

Just be careful you don’t call init more than once, and child classes invoke their parents’ constructors.