PHP object properties

Question

I'm new to OOP in PHP and I find the difference between the following two expressions difficult to understand.

    $object->$foo;
    $object->foo;

Maybe it's my fault, but I could not find the relevant part in the manual.

Answer 1

The first call $obj->$foo is using a so called variable variable. Check this:

class A { 
    public $foo = 1;
}

$a = new A();
$foo = 'foo';

// now you can use both
echo $a->$foo;
echo $a->foo;

Follow the manual about variable variables