Is there a special object initializer construct in PHP like there is now in C#?

问题

I know that in C# you can nowadays do:

var a = new MyObject
{
    Property1 = 1,
    Property2 = 2
};

Is there something like that in PHP too? Or should I just do it through a constructor or through multiple statements;

$a = new MyObject(1, 2);

$a = new MyObject();
$a->property1 = 1;
$a->property2 = 2;

If it is possible but everyone thinks it's a terrible idea, I would also like to know.

PS: the object is nothing more than a bunch of properties.

回答1:

As of PHP7, we have Anonymous Classes which would allow you to extend a class at runtime, including setting of additional properties:

$a = new class() extends MyObject {
    public $property1 = 1;
    public $property2 = 2;
};

echo $a->property1; // prints 1

Before PHP7, there is no such thing. If the idea is to instantiate the object with arbitrary properties, you can do

public function __construct(array $properties)
{
    foreach ($properties as $property => $value) 
    {
        $this->$property = $value
    }
}

$foo = new Foo(array('prop1' => 1, 'prop2' => 2));

Add variations as you see fit. For instance, add checks to property_exists to only allow setting of defined members. I find throwing random properties at objects a design flaw.

If you do not need a specific class instance, but you just want a random object bag, you can also do

$a = (object) [
    'property1' => 1,
    'property2' => 2
];

which would then give you an instance of StdClass and which you could access as

echo $a->property1; // prints 1

回答2:

I suggest you use a constructor and set the variables you wish when initialising the object.

回答3:

I went from c# to PHP too, so I got this working in PHP:

$this->candycane = new CandyCane(['Flavor' => 'Peppermint', 'Size' => 'Large']);

My objects have a base class that checks to see if there's one argument and if it's an array. If so it calls this:

public function LoadFromRow($row){
    foreach ($row as $columnname=>$columnvalue)
        $this->__set($columnname, $columnvalue);
}

It also works for loading an object from a database row. Hence the name.

回答4:

Another way, which is not the proper way but for some cases okay:

class Dog
{
    private $name;
    private $age;

    public function setAge($age) {
        $this->age = $age;
        return $this;
    }

    public function getAge() {
        return $this->age;
    }

    public function setName($name) {
        $this->name = $name;
        return $this;
    }

    public function getName() {
        return $this->name;
    }
}

$dogs = [
    1 => (new Dog())->setAge(2)->setName('Max'),
    2 => (new Dog())->setAge(7)->setName('Woofer')
];

来源：https://stackoverflow.com/questions/3837924/is-there-a-special-object-initializer-construct-in-php-like-there-is-now-in-c

标签

php

oop

constructor

initialization