Every class must have a constructor [duplicate]

  

Does every class need to have a constructor?

No. In PHP, classes can be declared without the definition of a constructor. In the meantime:

  

"Classes that have a constructor method call this method each time a new object is created, so it is appropriate for any startup the object might need before it is used."    PHP: Builders and Destructors

Therefore, it is recommended that you use the constructor to initialize attributes that are commonly bound to all methods of the class.

If the attribute is specific to a method, initialize it at invocation of the method itself.

  

(...)   Because if the constructor gets the properties of the whole class   access to some method of it, I will have to pass all the   values (name, age, rm), even if only to disable ().

I do not fully understand your statement. It is important to understand that whenever a class is instantiated with attributes initialized by the constructor, these properties will be available to any method of the object until it is destroyed.

No, no need.

The constructor simply serves to initialize class attributes.

The stdClass class, for example, does not have the __construct method.

In some cases, it is better to have a constructor than to have methods of type mutator and accessor .

Example with constructor:

class Aluno
{
   protected $nome;

   protected $idade;

   public function __construct($nome, $idade)
   {
       $this->nome = $nome; 

       $this->idade = $idade;
   }
}

Example without constructor:

class Aluno
{
   protected $nome;
   protected $idade;

   public function setNome($nome)
   {
      $this->nome = $nome;

   }

   public function setIdade($idade)
   {
      $this->idade = $idade;
   }

}