Inherit the properties in PHP

class Super{
 private $property;

 function __construct($set){
 $this->property = $set;
 }
}

class Sub extends Super{
 private $sub_property

 function __construct(){
 parent::__construct();
 $this->sub_property = $this->property;
 }
}

Notice: Undefined property: Sub::$property in sub.php on line 7

$this->sub_property = $this->property;

protected $property;

class Sub extends Super

I have a super class which contains properties & methods to set them

class Super{
 private $property;

 function __construct($set){
 $this->property = $set;
 }
} 

Then I have a subclass that needs to use this property

class Sub extends Super{
 private $sub_property

 function __construct(){
 parent::__construct();
 $this->sub_property = $this->property;
 }
}

But I keep getting errors

Notice: Undefined property: Sub::$property in sub.php on line 7

Where did I go wrong?

The error is that it is trying to find a local variable named $property, which does not exist.

To To refer to $property in the object context according to your intentions, you need $this and arrows.

$this->sub_property = $this->property;

< p>Secondly, the above line will fail because $property is a private property of the Super class. Change it to make it protected, so it is inherited.

protected $property; 

Third, (thanks to Merijn, I missed this), Sub needs to extend Super.

class Sub extends Super