Can I instantiate a PHP class inside another class?

Question

I was wondering if it is allowed to create an instance of a class inside another class.

Or, do I have to create it outside and then pass it in through the constructo

Answer 1

I just wanted to point out that it is possible to load a class definition dynamically inside another class definition.

Lukas is right that we cannot define a class inside another class, but we can include() or require() them dynamically, since every functions and classes defined in the included file will have a global scope. If you need to load a class or function dynamically, simply include the files in one of the class' functions. You can do this:

function some()
{
    require('db.php');
    $db = new Db();
    ...
}

http://php.net/manual/en/function.include.php