inheritance - PHP: How to call private values of parent construct in child construct? -

I want to be able to set the value of a personal property in the parent manufacturer, and the value of a child's creator or method I want to call.

For example:

  & lt ;? Php table class main class {Private $ prop_1; Private $ prop_2; Function __construct () {$ this-> Prop_2 = 'this' is prop_2 'property'; }} Class sub-class increases the main square {function __construct () {origin: __ creation (); $ This- & gt; Prop_1 = 'this' is propi 'property'; } Public Function GetBothProperties () {Return Array ($ this-> prop_1, $ this-> prop_2); }} $ Subclass = new sub-class (); Print_r ($ subclass-> GetBothProperties ()); ? & Gt;   
 Output:  
  array ([0] => this is the "prop_1" property [1] = & gt;)   
 However, if I change  prop_2  to  protected , the output will be:  
  Array ([0 ] = & Gt; This is the "prop_1" property [1] => this is the "prop_2" property)   
 I have  basic  the OO and PHP's Knowledge is there, but I can not understand that by calling (or shown) when calling it  prop_2  it is  private ; This can not be a private / public / protected problem because 'prop_1' is private and able to call and show ... right?  
 Is this the issue of assigning values ​​to the parent class vs parent class?  
 I help understand why.  
 Thank you. P>  
 
 
 The private property of the guardian class can not be used in the child class and vice versa.  
 You can do this  
  Abstract class main category {Private $ prop_1; Private $ prop_2; Function __construct () {$ this-> Prop_2 = 'this' is prop_2 'property'; } Secure Function Set ($ name, $ value) {$ this- & gt; $ Name = $ value; } Get a secure function ($ name) {return $ $ -> $ name; }} Class sub-class increases the main square {function __construct () {origin: __ creation (); $ This- & gt; Set ('prop_1', 'this' is prop_1 "property ');} public function GetBothProperties () {get return array ($->' prop_1 '), get $ this-> (' Prop_2 '));}}