Analysis of differences between New static () and new self () in PHP

This article describes the difference between the new static () and the New self () in PHP, and I believe that it will help you to learn PHP programming.

The problem was caused by building a station locally. Found in PHP 5.2 is not built up, the station PHP code inside there are a lot of more than 5.3 parts, requiring changes to run at 5.2.

Changed to find a place.

return New Static ($val);

This is a horse of God, I saw

return new self ($val);

Class A {public  static function get_self () {    return to new self ();  }   public static function Get_static () {    return new static ()  }} class B extends A {} echo Get_class (B::get_self ()); Aecho Get_class (B::get_static ()); Becho Get_class (A::get_static ()); A

　　

So the internet looked down, the difference between them two.

Self-Is this class, which is the class within the code snippet.

Static-php 5.3 Added only the current class, a bit like the meaning of $this, extracted from the heap memory, access to the current instantiation of the class, then static represents the class.

Or look at the professional explanation of the foreigner:

Self refers to the same class whose method, the new operation takes place in.

Static in PHP 5.3 's late static bindings refers to whatever class in the hierarchy which the method on.

In the following example, B inherits both methods from A. Self is bound to a because it's defined in a ' s implementation of The first method, whereas static is bound to the called Class (also see Get_called_class ()).

classA { Public Staticfunction get_self () {return NewSelf (); }    Public Staticfunction get_static () {return New Static(); }} classB extends A {} echo Get_class (B::get_self ());//AEcho Get_class (B::get_static ());//BEcho Get_class (A::get_static ());//A

This example is basically understood at a glance.

Class A {public  function create1 () {    $class = Get_class ($this); return new $class ();  }  Public Function Create2 () {    return new static ();  

　　

The principle is understood, but the problem has not been solved, how to resolve the return new static ($val); What about the problem?

In fact, it is simple to use Get_class ($this); The code is as follows:

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Analysis of differences between New static () and new self () in PHP