Classes & objects behaviors testing in php5

1. //File: a.php
   
2. class a{
   
3. 
   
4.         static public function func_a(){
   
5.                 class b{
   
6.                         public function func_b(){
   
7.                                 echo 'executing class b function func_b';
   
8.                         }
   
9.                 }
   
10.         }
    
11. 
    
12. }
    
13. 
    
14. a::func_a();
    
15. b::func_b();

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---> Fatal error: Class declarations may not be nested in D:\xampplite\htdocs\lab\class\a.php on line 5

1. //File: a.php
   
2. class a{
   
3. 
   
4.         static public function func_a(){
   
5.                 eval("class b{
   
6.                         public function func_b(){
   
7.                                 echo 'executing class b function func_b';
   
8.                         }
   
9.                 }");
   
10.         }
    
11. 
    
12. }
    
13. 
    
14. a::func_a();
    
15. b::func_b();

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---> executing class b function func_b

1. //File: a.php
   
2. class a{
   
3. 
   
4.         static public function func_a(){
   
5.                 include 'b.php';
   
6.         }
   
7. 
   
8. }
   
9. 
   
10. a::func_a();
    
11. b::func_b();
    
12. 
    
13. //File: b.php
    
14. class b{
    
15.         public function func_b(){
    
16.                 echo 'executing class b function func_b';
    
17.         }
    
18. }

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---> executing class b function func_b

------------------

function & method behaviors

1. class a{
   
2. 
   
3.         public static function func_a(){
   
4.                 function func_c(){
   
5.                         echo 'executing class a function func_c';
   
6.                 }
   
7.         }
   
8. 
   
9. }
   
10. 
    
11. a::func_a();    //call to define nested function
    
12. 
    
13. 
    
14. func_c();
    
15. a::func_c();

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func_c(); -> executing class a function func_c
a::func_c(); -> Fatal error: Call to undefined method a::func_c() in D:\xampplite\htdocs\lab\class\a.php on line 14

conclusion: define a function in a method will be a global function but another method, same as being defined by eval.

-------------------

about $this, seems it's readonly

1. class a{
   
2. 
   
3.         public function b(){
   
4.                 $this = new c();
   
5.                 $this->d();
   
6.         }
   
7. 
   
8. }
   
9. 
   
10. class c{
    
11. 
    
12.         public function d(){
    
13.                 echo 'xxx';
    
14.         }
    
15. 
    
16. }
    
17. 
    
18. $a = new a();
    
19. 
    
20. $a->b();

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---> Fatal error: Cannot re-assign $this in D:\xampplite\htdocs\lab\class\index.php on line 5