PHP new static and new self, staticself

PHP new static and new self, staticself

Recently, I was asked a small question in a video comment: Is there any special consideration for static instead of self? Or we can convert the problem as follows:

What are PHP's new static and new self?

In fact, the following example should be clear:

class Father { public static function getSelf() {  return new self(); } public static function getStatic() {  return new static(); }}class Son extends Father {}echo get_class(Son::getSelf()); // Fatherecho get_class(Son::getStatic()); // Sonecho get_class(Father::getSelf()); // Fatherecho get_class(Father::getStatic()); // Father

Pay attention to this line.get_class(Son::getStatic());The returned result isSonThis class can be summarized as follows:

New self

1.selfThe returned result isnew selfMedium keywordnewIn the class, for example:

Public static function getSelf () {return new self (); // The new Keyword is in Father}

Always returnFather.

New static

2.staticOn the basis of the above, it is a little smarter:staticWill return executionnew static()Class, suchSonRunget_class(Son::getStatic())The returned result isSon,FatherRunget_class(Father::getStatic())The returned result isFather

In the absence of inheritance, we can consider thatnew selfAndnew staticReturns the same result.

Tips: You can use a good IDE to directly view comments. For example, PhpStorm:

Happy Hacking