How can changes made in one class instance affect another class instance in PHP?

Changes made in one class instance can affect another class instance if the properties of the class are declared as static. Static properties are shared among all instances of a class, so any changes made to a static property in one instance will be reflected in all other instances of the class. 

class MyClass {
    public static $sharedProperty = 0;
}

$instance1 = new MyClass();
$instance2 = new MyClass();

$instance1::$sharedProperty = 10;

echo $instance2::$sharedProperty; // Output: 10

Keywords

PHP class instance object-oriented programming reference pass by reference

Related Questions