PHP new static and new self

Use self:: or __class__ a static reference to the current class, depending on the class in which the current method is defined: Using static:: Is no longer resolved to define the class in which the current method resides, but is evaluated at the actual run time. It can also be called a "static binding" because it can be used (but not limited to) the invocation of a static method.

A recent comment in a video was asked a small question: Is there a special consideration for static instead of self? Or we can change the question like this:

What is the new static and new self of PHP specific?

In fact, this one example should be very clear:

Class Father {public static function getself () {  return to 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

Note that this line get_class(Son::getStatic()); returns the Son class, which can be summed up as follows:

New self

1. self returns the class in which the new self keyword is new located, as in the example here:

public static function Getself () {  return new self ();//New keyword is here in Father}

Always returns Father .

New static

2. static on the above basis, a little bit smarter: The static class that will return execution new static() , such as execution returns, is the Son execution that get_class(Son::getStatic()) Son Father get_class(Father::getStatic()) returns theFather

In the case of no inheritance, the same result can be considered new self and new static returned.

Tips: You can use a good IDE to see the annotations directly. such as Phpstorm: