What is PHP\'s `::class` and How Does it Improve Code Clarity and Management?

Understanding ::class in PHP: A Versatile Tool for Class Manipulation

Many developers may be unfamiliar with the mysterious ::class notation in PHP due to its cryptic nature. Let's delve into what it is and how it benefits developers.

What is ::class?

The ::class syntax in PHP enables us to retrieve the fully qualified name of a class, including its namespace. This feature was introduced in PHP 5.5.

Advantages of Using ::class

This notation offers two primary advantages:

1. Improved Code Clarity and Management: Instead of storing class names as strings in your code, you can utilize the ::class notation. This approach enhances code readability and facilitates refactoring, as IDEs can automatically update class names.
2. Use Keyword Compatibility: When used with the use keyword, the ::class notation allows you to reference classes without specifying their full names. For example:

use \App\Console\Commands\Inspire;

//...

protected $commands = [
    Inspire::class, // Equivalent to "App\Console\Commands\Inspire"
];

Additional Benefits

In addition to the aforementioned advantages, the ::class notation also plays a crucial role in Late Static Binding. Unlike the CLASS magic constant, static::class enables the retrieval of the current class name within parent classes. This differentiation is particularly useful when dealing with class inheritance.

Example: Late Static Binding

class A {

    public function getClassName(){
        return __CLASS__;
    }

    public function getRealClassName() {
        return static::class;
    }
}

class B extends A {}

$a = new A;
$b = new B;

echo $a->getClassName();      // A
echo $a->getRealClassName();  // A
echo $b->getClassName();      // A
echo $b->getRealClassName();  // B

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