Question

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

Let’s look at this example (PHP):

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

Versus:

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");
}

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

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

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.

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

Answer 1

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

Also, look at the following examples:

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

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

On the other hand,

$class->setNaem('John');

will never work.