What is the differece between private and protected in OOP?

Question

I don't understand what is the different between private method and protected method in Object Oriented PHP. After make a method private , I'm able to access it from extends class. Please check the code below -

<?php

class person{

private function namedilam(){

    return "likhlam";

}

public function kicu(){

    return $this->namedilam();

}

}

class second extends person{

}

$info = new second;

echo $info->kicu();

It seems you're no accessing it directly. Are you able to call `$info->namedilam()`? — alayor, Jan 14 '17 at 06:31
you'r calling the public function kicu() not the private function namedilam() — Sepultura, Jan 14 '17 at 11:00
Possible duplicate of [What is the difference between public, private, and protected?](http://stackoverflow.com/questions/4361553/what-is-the-difference-between-public-private-and-protected) — dbrumann, Jan 14 '17 at 14:55

score 0 · Answer 1 · answered Jan 14 '17 at 11:47

The difference will become clear when you do it like this:

class Liam {
    private getFirstName() {
         return "Liam";
    }

    public function getName() {
        return $this->getFirstName();
    }
}

class Max extends Liam {
    private function getFirstName() {
         return "Max";
    }
}

class Peter extends Liam {
    public function getLiamsName() {
        return $this->getFirstName();
    }
}

$max = new Max();
echo $max->getName();
// returns "Liam", not "Max" as you might expect

$peter = new Peter();
echo $peter->getLiamsName();
// PHP Fatal error:  Uncaught Error: Call to private method Liam::getFirstName() [...]

Max will return "Liam" because the getName() calls getFirstName() in the Liam class, not the one from the class extending it. This means with private methods you can make sure that whenever in your class you call this method exactly this one is used and it will never be overwritten.

To explain it in general terms:

private methods are only accessible inside the class. They can not be overwritten or accessed from outside or even classes extending it.

protected methods are accessible inside the class and in extending classes, but you can't call them from outside like:

$max = new Max();
$max->iAmProtected();

This will neither work with private or protected methods.

What is the differece between private and protected in OOP?

1 Answers1