我不是PHP开发人员，所以我想知道在PHP中使用显式getter/setter的优点和缺点是什么，在纯OOP风格中，带有私有字段(我喜欢的方式):
class MyClass {
private $firstField;
private $secondField;
public function getFirstField() {
return $this->firstField;
}
public function setFirstField($x) {
$this->firstField = $x;
}
public function getSecondField() {
return $this->secondField;
}
public function setSecondField($x) {
$this->secondField = $x;
}
}
或者只是公共字段:
class MyClass {
public $firstField;
public $secondField;
}
封装在任何面向对象语言中都很重要，与受欢迎程度无关。在动态类型语言(如PHP)中，它特别有用，因为如果不使用设置符，几乎没有办法确保属性是特定类型的。
在PHP中，这是有效的:
class Foo {
public $bar; // should be an integer
}
$foo = new Foo;
$foo->bar = "string";
在Java中，它没有:
class Foo {
public int bar;
}
Foo myFoo = new Foo();
myFoo.bar = "string"; // error
使用魔法方法(__get和__set)也可以，但只有当访问的属性的可见性低于当前作用域可以访问的时候。如果使用不当，调试时很容易让您头疼。
在阅读了其他建议后，我倾向于这样说:
作为GENERIC规则，你不会总是为所有属性定义setter，特别是“内部”属性(信号量、内部标志……)。只读属性显然没有setter，所以有些属性只有getter;这就是__get()缩小代码的地方:
define a __get() (magical global getters) for all those properties which are alike,
group them in arrays so:
they'll share common characteristics: monetary values will/may come up properly formatted, dates in an specific layout (ISO, US, Intl.), etc.
the code itself can verify that only existing & allowed properties are being read using this magical method.
whenever you need to create a new similar property, just declare it and add its name to the proper array and it's done. That's way FASTER than defining a new getter, perhaps with some lines of code REPEATED again and again all over the class code.
是的!我们也可以写一个私有方法来做到这一点，但话又说回来，我们将声明许多方法(++内存)，最终调用另一个总是相同的方法。为什么不写一个单一的方法来管理它们呢?(是的!双关语!)):
Magic setter也可以只响应特定的属性，因此可以单独在一个方法中筛选所有日期类型属性的无效值。如果日期类型属性列在数组中，则可以轻松定义它们的setter。当然，这只是一个例子。有太多的情况。
About readability... Well... That's another debate: I don't like to be bound to the uses of an IDE (in fact, I don't use them, they tend to tell me (and force me) how to write... and I have my likes about coding "beauty"). I tend to be consistent about naming, so using ctags and a couple of other aids is sufficient to me... Anyway: once all this magic setters and getters are done, I write the other setters that are too specific or "special" to be generalized in a __set() method. And that covers all I need about getting and setting properties. Of course: there's not always a common ground, or there are such a few properties that is not worth the trouble of coding a magical method, and then there's still the old good traditional setter/getter pair.
编程语言就是人类的人工语言。因此，它们都有自己的语调或重音、语法和风格，所以我不会假装用与Java或c#相同的“重音”来编写Ruby或Python代码，也不会编写类似Perl或SQL的JavaScript或PHP……用他们该用的方式去使用他们。
