What is the PHP ::class Notation and How Does it Simplify Class Handling?

The ::class Notation in PHP: A Comprehensive Explanation

The ::class notation in PHP is a relatively recent addition to the language, introduced in version 5.5. This notation allows you to retrieve the fully qualified name of a class, including its namespace.

How to Use ::class

To use the ::class notation, simply write the name of the class followed by the ::class suffix:

SomeClass::class

This will return the full name of the class, such as:

App\Console\Commands\Inspire

Benefits of Using ::class

The ::class notation offers several advantages over traditional methods of storing class names:

• Eliminates the need for string literals: Instead of storing class names as strings, you can use the ::class notation, which will automatically generate the correct fully qualified name. This makes your code more robust and less error-prone.
• Improves IDE refactoring: Many IDEs can leverage the ::class notation to auto-complete class names and update them correctly during code refactoring.
• Simplifies usage with the use keyword: You can use the use keyword to alias class names, making it easier to work with them in your code. For example:

use App\Console\Commands\Inspire;

//...

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

Additional Applications of ::class

In addition to its primary function, the ::class notation can also be used for late static binding, a technique where the name of the derived class is resolved inside the parent class. This can be accomplished by using the static::class syntax:

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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