OOP In PHP (Object Oriented Programming in PHP)

This is a basic introduction on how to use OOP – Object Oriented Programming in PHP, as requested by a friend.

Declaring a Class

class myClass {
    // Class contents go here
}

Instantiating an Object

$myClassInst = new myClass();

OOP Class Inheritance

class a {
    function test() {
        echo "a::test called";
    }

    function func() {
        echo "a::func called";
    }
}

class b extends a {
    function test() {
        echo "b::test called";
    }
}

class c extends b {
    function test() {
        parent::test();
    }
}

class d extends c {
    function test() {
        b::test();
    }
}

$a = new a();
$b = new b();
$c = new c();
$d = new d();

$a->test(); // Outputs "a::test called"
$b->test(); // Outputs "b::test called"
$b->func(); // Outputs "a::func called"
$c->test(); // Outputs "b::test called"
$d->test(); // Outputs "b::test called"