值对象与PHP中的关联数组 [英] Value objects vs associative arrays in PHP

问题描述

(此问题使用PHP作为上下文，但不仅限于PHP.例如，任何内置哈希值的语言也都适用)

(This question uses PHP as context but isn't restricted to PHP only. e.g. Any language with built in hash is also relevant)

让我们看一下这个示例(PHP):

Let's look at this example (PHP):

function makeAFredUsingAssoc()
{
    return array(
        'id'=>1337,
        'height'=>137,
        'name'=>"Green Fred");
}

对:

class Fred
{
    public $id;
    public $height;
    public $name;

    public function __construct($id, $height, $name)
    {
        $this->id = $id;
        $this->height = $height;
        $this->name = $name;
    }
}

function makeAFredUsingValueObject()
{
    return new Fred(1337, 137, "Green Fred");
}

方法1当然很麻烦，但是它很容易导致诸如以下的错误

Method #1 is of course terser, however it may easily lead to error such as

$myFred = makeAFredUsingAssoc();
return $myFred['naem']; // notice teh typo here

当然，有人可能会说$myFred->naem同样会导致错误，这是事实.但是，对我来说，上正规课对我来说比较僵硬，但是我不能为它辩护.

Of course, one might argue that $myFred->naem will equally lead to error, which is true. However having a formal class just feels more rigid to me, but I can't really justify it.

使用每种方法的利弊是什么?人们何时应该使用哪种方法?

What would be the pros/cons to using each approach and when should people use which approach?

推荐答案

在表面上，这两种方法是等效的.但是，使用类时，您将获得大多数标准的OO好处:封装，继承等.

Under the surface, the two approaches are equivalent. However, you get most of the standard OO benefits when using a class: encapsulation, inheritance, etc.

另外，请看以下示例:

$arr['naem'] = 'John';

完全有效，可能很难找到它.

is perfectly valid and could be a difficult bug to find.

另一方面，

$class->setNaem('John');

将永远无法工作.

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