Question

class Bar{        
    public function test(){
        $this->testPublic();
        $this->testPrivate();
    }

    public function testPublic(){
        echo "Bar::testPublic\n";
    }

    private function testPrivate(){
        echo "Bar::testPrivate\n";
    }        
}

class Foo extends Bar{
    public function testPublic(){
        echo "Foo::testPublic\n";
    }
    private function testPrivate(){
        echo "Foo::testPrivate\n";
    }

}

$myFoo = new Foo();
$myFoo->test();
//Foo::testPublic
//Bar::testPrivate

I’m having a lot of trouble understanding this output. Would someone be able to give me a clear succinct explanation of what is going on? I’m learning OOP and wanted to know how to use extensions to override the parent class functions.

Answer 1

The test() method calls 2 methods:

1. testPublic – it’s a public one, so it was overriden in the Foo. So the Foo::testPublic is called
2. testPrivate – it’s a private one, so it’s only visible for each class itself. For the caller method (it’s Bar) – it’s a Bar::testPrivate

So – if the method is public or protected – it can be overriden and called from the ancestor/child; if it’s private – it cannot.