PHP的 类名::class 是啥？

This feature was implemented in PHP 5.5.Documentation :http://php.net/manual/en/migration55.new-features.php#migration55.new-features.class-name It's very useful for 2 reasons.

• You don't have to store your class names in strings anymore. So, many IDEs can retrieve these class names when you refactor your code
• You can use theusekeyword to resolve your class and you don't need to write the full class name.

For exemple :

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

Update:This feature is also useful forLate Static Binding.Instead of using the__CLASS__magic constant, you can use thestatic::classfeature to get the name of the derived class inside the parent class. For example:

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

来源：https://stackoverflow.com/questions/30770148/what-is-class-in-php