Subclasses use parent class variables to solve ideas

Subclasses use parent class variables
Class A {
var $authKey = ' 1111 ';

}

Class B extends a{
__construct () {
Echo Parent::authkey;
}
}
Error undefined class constant ' AuthKey '

------Solution--------------------
The error message means a constant that is undefined. You're missing a $.
But $authkey is not a static variable, so you can't call it so statically
The right approach

PHP code

class A {//Do not recommend using VAR in class to declare the variable public $authKey = ' 1111 ';}   Class B extends a{//b will have all non-private members of a public function __construct () {echo $this->authkey; }} 
------solution--------------------
 Var was in the previous version of PhP4 and was later omitted. 
------Solution--------------------
 var is best taken with the case! Some of the lower versions support 
------Solutions--------------------
 var is php 4.X,, 5+ used in order to backward compatibility, 
 
 New program, basically can give up this type of writing 
 
 Your code can also use 
 
   
   

    
     PHP code 
    
    
class A {const authkey= ' 1111 ';} Class B extends a{public function __construct () {echo parent::authkey;}} New B; 
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