New self vs new static

Question

I am converting a PHP 5 3 library to work on PHP 5 2  The main thing standing in my way is the use of late static binding like return new static  options     if I convert this to return new self  options  will I get the same results   What is the difference between new self and new static

User · Answer

If the method of this code is not static, you can get a work-around in 5.2 by using get_class($this).

class A {
    public function create1() {
        $class = get_class($this);
        return new $class();
    }
    public function create2() {
        return new static();
    }
}

class B extends A {

}

$b = new B();
var_dump(get_class($b->create1()), get_class($b->create2()));

The results:

string(1) "B"
string(1) "B"

User · Answer

In addition to others  answers       static   will be computed using runtime information    That means you can t use static   in a class property because properties values       Must be able to be evaluated at compile time and must not depend on run-time information    class Foo       public  name   static  class       Foo   new Foo  echo  Foo- gt name     Fatal error   Using self      class Foo       public  name   self  class      Foo   new Foo  echo  Foo- gt name     Foo      Please note that the Fatal error comment in the code i made doesn t indicate where the error happened  the error happened earlier before the object was instantiated as  Grapestain mentioned in the comments

User · Answer

will I get the same results    Not really  I don t know of a workaround for PHP 5 2  though      What is the difference between new self and new static    self refers to the same class in which the new keyword is actually written   static  in PHP 5 3 s late static bindings  refers to whatever class in the hierarchy you called the method on   In the following example  B inherits both methods from A  The self invocation 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      class A       public static function get self             return new self               public static function get static             return new static             class B extends A     echo get class B  get self         A echo get class B  get static        B echo get class A  get self        A echo get class A  get static        A

[php] New self vs. new static

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