php - 使用 == 运算符在对象比较期间忽略选定的类成员

Question

PHP 提供了一种非常好的对象比较方法。

class People {
    public $name;
}

$p0 = new People();
$p1 = new People();

$p0->name = 'ali';
$p1->name = 'ali';

// equal
if ($p0 == $p1) {
    echo 'equal' . "\n";
} else {
    echo 'diff' . "\n";
}

但是，有时，我希望在比较过程中忽略一些类成员。

class People {
    public $id;
    public $name;
}

$p0 = new People();
$p1 = new People();

$p0->id = 0;    // Can we ignore this id during == comparison?
$p1->id = 1;    // Can we ignore this id during == comparison?
$p0->name = 'ali';
$p1->name = 'ali';

// diff. As $p0->id != $p1->id. How can we ignore id during == comparison?
if ($p0 == $p1) {
    echo 'equal' . "\n";
} else {
    echo 'diff' . "\n";
}

是否有办法让我要求 == 运算符忽略选定的类成员？

Answer 1

您不能在 PHP 中重载运算符。有一个PECL extension允许它，但更容易(也更便携)为您的对象提供一个 equals() 方法，然后通过它进行比较，例如

class People
…
    public function equals(People $people)
    {
        return $this->name === $people->name;
    }
}