Php: Access static properties from super classes

In Php, static properties and methods are inherited. If you update the value of a static property same will be reflected to all the subclasses and this class.

 

static_data_inheritance.php

#!/usr/bin/php

<?php

    class ParentClass{
        public static $name = 'Parent class';
    }

    class ChildClass1 extends ParentClass{

    }

    class ChildClass2 extends ParentClass{

    }

    class ChildClass3 extends ChildClass2{

    }

    function print_name(){
        $name1 = ParentClass::$name;
        $name2 = ChildClass1::$name;
        $name3 = ChildClass2::$name;
        $name4 = ChildClass3::$name;

        echo "\nParentClass : $name1\n";
        echo "ChildClass1 : $name1\n";
        echo "ChildClass2 : $name1\n";
        echo "ChildClass3 : $name1\n";
    }
   
    print_name();

    echo "\nUpdating name using ChildClass1\n";
    ChildClass1::$name = "Child class1";

    print_name();

?>

 

Output

$./static_data_inheritance.php 


ParentClass : Parent class
ChildClass1 : Parent class
ChildClass2 : Parent class
ChildClass3 : Parent class

Updating name using ChildClass1

ParentClass : Child class1
ChildClass1 : Child class1
ChildClass2 : Child class1
ChildClass3 : Child class1

 

  

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