Is it possible to have python rich comparison in php? - php

Question

One of my dreams is to use python rich comparison (something like __eq__) on php objects.
class A {
public $a = 1;
public function __eq__($other) {
return $this->a == $other->a;
}
}
class B {
public $a = 2;
public function __eq__($other) {
return $this->a == $other->a;
}
}
class C {
public $a = 1;
public function __eq__($other) {
return $this->a == $other->a;
}
}
$a = new A();
$b = new B();
$c = new C();
echo $a == $b; //false
echo $a == $c; //true
I'd like to have some smart mechanism to fast-compare models (objects) on database id, for example.
Is it possible in some way in PHP?

Answer 1

No, it isn't. A common way to achieve this is to use an equals() method, but there isn't any magic method. You'll have to call it manually. For example:
<?php
class User
{
private $id;
public function __construct($id)
{
$this->id = $id;
}
public function getId()
{
return $this->id;
}
public function equals(User $user)
{
return $this->getId() === $user->getId();
}
}
$user1 = new User(1);
$user2 = new User(2);
var_dump($user1->equals($user2)); // bool(false)
var_dump($user2->equals($user1)); // bool(false)
?>
Which, I think, isn't much different from:
var_dump($user1 == $user2);
var_dump($user2 == $user1);
Anyway, my example will work even using the == operator, since it will compare the values of all the properties.