Примеры базового использования абстрактных классов PHP

php
// The abstract class is like a template for subclass extension (rewriting). There are common methods (method bodies) and abstract methods in the abstract class, in which the abstract method has no method bodies and ends with a semicolon.
// As long as there is an abstract method, this class must be defined as an abstract class.
// An abstract class cannot create its own instance, and when it tries to create an abstract class object, it generates an error.
// Implementing methods of abstract classes in subclasses is equal to and higher than the visibility of abstract methods, abstract classes (public | protected | private), and subclasses (public | public, protected | have fatal errors and cannot be inherited).
// abstract classes cannot define private methods, but can define private attributes.
// If subclasses do not extend (rewrite) the abstract methods of abstract classes, errors will occur.
abstract class Employees{
  protected $name = null;
  function __construct($nameStr){
    $this->name = $nameStr;
  }
  abstract public function work();
  public function work1(){
    echo "
$this->name
";
  }
  //function __destruct(){}
}
class Managers extends Employees{
  public function __construct($nameStr){
    parent::__construct($nameStr);
  }
  /*public function work(){// If subclasses do not extend (rewrite) the abstract methods of abstract classes, errors will occur.
    echo "
$this->name is working
";
  }*/
}
// $obj1 = new Employees (); // When creating abstract class objects, a resulting error occurs.
$obj2 = new Managers('e2');
//$obj2->work();

name = $nameStr;
  }
  abstract public function work();
  public function work1(){
    echo "
$this->name
";
  }
  //function __destruct(){}
}
class Managers extends Employees{
  public function __construct($nameStr){
    parent::__construct($nameStr);
  }
  public function work(){// If subclasses do not extend (rewrite) the abstract methods of abstract classes, errors will occur.
    echo "
$this->name is working
";
  }
}
// $obj1 = new Employees (); // When creating abstract class objects, a resulting error occurs.
$obj2 = new Managers('e2');
$obj2->work();