Yii2中:: class vs :: className（）之间的区别？

Question

i know both gives same results but i am looking forward to hear about performance.

i am not sure but i think..

• "MyClass::className()" cause that class file to be loaded as well (its Yii function whom body is just simply get_called_class())

• "MyClass::class" i think this php's native class property don't load class php file and just return its name based on current namespace or use.

Let me know if i am right? or highlight your knowledge please.

There are many places where we just want full qualitfied class name even it's not going to be used that time. but i also don't like putting hardcoded strings (due to hard refactoring)

Answer 1

Yes i just found i was right.

PHP's native class property is performance saving..(PHP 5.5+)

see here http://php.net/manual/en/language.oop5.basic.php#language.oop5.basic.class.class.name

so this don't cause class file to be loaded, so even if class doesn't exists it will return full className

Note: The class name resolution using ::class is a compile time transformation. That means at the time the class name string is created no autoloading has happened yet. As a consequence, class names are expanded even if the class does not exist. No error is issued in that case.