php - Echo variable which has been set in another classes function -

i trying access contents of variable class. have code below, expecting 'test' returned, nothing.

i assume because getting $abc_rank empty. required variable populated in function itself.

therefore how can $abc_rank hold echo , output via other class?

<?php  class class1 {      public static $abc_rank;      public function __construct() {         $this->add_text();     }      public function add_text() {         $this->abc_rank = 'test';     }  }  class class2 {      public function __construct() {         $this->display();     }      public function display() {         $test = class1::$abc_rank;         echo $test;      }  }  $go = new class2();  ?> 

i know can do:

public static $abc_rank = 'test'; 

but population of variable must in function.

i have read of other related answers , can't seem work.

in class1 :

replace $this->abc_rank = 'test'; $this::$abc_rank='test';

($abc_rank static property)

in class2 :

in display function : replace

$test = class1::$abc_rank; echo $test;  

with

$test = new class1(); echo $test::$abc_rank; 

(class1 isn't static)

full code here :

class class1 {      public static $abc_rank;      public function __construct() {         $this->add_text();     }      public function add_text() {         //$this->abc_rank = 'test';         $this::$abc_rank='test';     }  }  class class2 {      public function __construct() {         $this->display();     }      public function display() {         //$test = class1::$abc_rank;         //echo $test;          $test = new class1();         echo $test::$abc_rank;     }  }  $go = new class2();