PHP OOP , discovered something that I don't understand why it's happening

PHP
1

part of the codes

in class file



class Address {
		public $_house_number; //notice this one has underscore here
}

public function AddressDetails(){
		
		$output ="<h1> House number </h1>";
		$output .= $this->house_number; //notice no underscore here

                echo $output;
		
		}

in front page



<?php
include('address.class.inc');

$address = new Address();
$housenumber= $address->house_number=10; //notice no underscore in front, so value set to the no underscore version

 $address->AddressDetails();

The question is how come I was able to set value to the property which I didn’t declare just under class declaration. In fact even if I don’t declare public $_house_number; at top it still works.

2

Yeah, this can be done in php. Even though it’s a bad practice to not declare instance variables before setting their value, it can be done.

3

Php allows you to declare and assign properties on the fly, although the visibility will always be public so you lose the power of encapsulation.

4

It’s not a bad practice in php. It’s a feature.

5

I found about it when I was watching overloading tutorial. Is that’s what this feature called?

6