[RESOLVED] implicit constructor call???

kakki

hello, i have a question:

does php call the constructor of a class in its subclass automatic if i leave out the
constructor method of the subclass???

examancer

I don't think so. PHP I believe will only call the constructor method for the class your are initializing, not any subclasses.

You could test the theory pretty easily though... I would if I wasn't at work...

thorpe

No. And even if you do create a construct in the child, you still need to explicitly call the parents construct within it. eg;

class foo {
  function __construct() {
    echo "this is foo\n";
  }
}
class bar extends foo {
  function __construct() {
    parent::__construct();
    echo "this is bar\n";
  }
}

kakki

examancer wrote:
You could test the theory pretty easily though... I would if I wasn't at work...

me as well, but i meant:

class Foo
{
	function Foo()
	{
		echo 'constructor foo<br />';
	}
}
class Bar extends Foo
{

}

$foo=new Foo();

does that output or not???
(it does)

BTW:
1)does this "magic "-thing work faster than the "traditional" constructor with the name of the class in it?
2) what if i call parent::Foo() in Bar and i named that thing constructor???

examancer

in your example, the echo() statement should execute and be output, but only because you are initializing an instance of the Foo class, which is a subclass of Bar. If you did $foo = new Bar(); the echo statement would not output.

examancer

BTW... i don't think using contructor would be significantly faster, but it may be a little faster. And you can have a contstuctor in both Foo and Bar, and have Bar call Foo's constructor inside of Bar's constructor using parent::__constructor() and it shouldn't be a problem.

kakki

ok i changed that to:

class Foo
{
	function foo()
	{

	echo get_class( $this ); 
}
}
class Bar extends Foo
{

}

$foo=new Bar();

and it still echos ....( in this case 'Bar' ) ...

thorpe

does php call the constructor of a class in its subclass automatic if i leave out the
constructor method of the subclass???

Actaully... I was wrong. Yes, it does.

from the manual wrote:
Parent constructors are not called implicitly if the child class defines a constructor.

That suggests to me that a parents __construct will be called if the child does not define one.

kakki

thanks everybody...

i will spend more time on this oop ...