CODEWITHSUNDEEP
phparrays
user2064000
user2064000

Reputation:

extract() for class members

There's the extract function for generating local variables from an array:

extract(['a' => 10, 'b' => 20]) // $a = 10, $b = 20

What would be a clean solution like the extract() function, but for class members? Obviously I can do something along the lines of:

class User {
  private $user_id;
  private $password;
  private $email;

  public function __construct($params) {
    $this->user_id = isset($params['user_id']) ? $params['user_id'] : null;
    $this->password = isset($params['password']) ? $params['password'] : null;
    $this->email = isset($params['email']) ? $params['email'] : null;
  }
}

Is there a cleaner way to do this?

Upvotes: 2

Views: 48

Answers (2)

axiac
axiac

Reputation: 72226

The cleanest way to do it is to avoid arrays and extract() altogether and pass the constructor individual arguments:

public function __construct($user_id, $password, $email)
{
    // Add validation and default values for each member as needed
    $this->user_id  = $user_id;
    $this->password = $password;
    $this->email    = $email;
}

This way, another programmer1 that reads the code understands from a glance what arguments the constructor expects and what is their meaning.

It also makes the code that uses the class more clear. Compare:

$user = new User($id, $_POST['password'], $_POST['email']);

with:

$user = new User($_POST);

In the first case you don't have to read the code of class User to understand why it fails or produces unexpected results. A quick peek on the content of $_POST is enough to know if the values passed to User::__construct() are the ones it expects.

1 The "other programmer" could (and most of the times will) be you, several months later.

Upvotes: 0

AbraCadaver
AbraCadaver

Reputation: 78994

A simple solution that behaves like extract():

foreach($params as $key => $val) {
    $this->$key = $val;
}

Upvotes: 4

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