Difference between public, protected, and private: protectedprivate

Difference between public, protected, and private: protectedprivate

Use className: functionNmae (), instantiation, parent, and self to draw a conclusion.

ClassName: functionNmae () must be a static method (public Mode)

Parent: functionNmae () the parent class must be a static method (public or protected)

Self: functionNmae () This class must be a static method (three modes)

Instantiation: after instantiation, you can access static or common methods in public mode.

 

1. Direct Access (via className: functionNmae () and instantiation ):

Conclusion:

| It can be accessed through className: functionNmae ()
Public
| It can be accessed through instance $ obj-> functionName ()

| Cannot be accessed through className: functionNmae ()
Protected
| Cannot be accessed through instance $ obj-> functionName ()

| Cannot be accessed through className: functionNmae ()
Private
| Cannot be accessed through instance $ obj-> functionName ()

<? Php/*** @ authors HG (hg0728@qq.com) * @ date 17:12:02 * @ version 1.0 */header ("Content-type: text/html; charset = UTF-8 "); class A {static $ name = 'This is the static variable of class A'; static public function stc_pc () {echo 'This is the public static method of class A <br/> ';} static function stc () {echo 'This is A static method of Class A <br/>';} static protected function stc_pd () {echo 'This is A protected static method of Class A <br/>';} static private function stc_pe () {echo 'This is A private static method of Class A <br/>';} A: stc_pc (); // you can access A: stc (); // accessible A: $ name; // No error/A: stc_pd (); // inaccessible // A: stc_pe (); // inaccessible echo '<br> access through instantiation <br>'; $ a = new A (); $ a-> stc_pc (); // accessible $ a-> stc (); // accessible // $ a-> $ name; // error // $ a-> stc_pd (); // inaccessible // $ a-> stc_pe (); // inaccessible/********************* | you can use className: functionNmae () access public | access through instance $ obj-> functionName () | protected cannot be accessed through className: functionNmae () | access through instance $ obj-> functionName () access | private cannot be accessed through className: functionNmae () | the instance $ obj-> functionName () cannot be used () access ********************/

2. Direct Access (self: functionNmae ())

Conclusion:

Self: functionNmae (); must be a static method (either of the three modes)

<? Php/*** @ authors HG (hg0728@qq.com) * @ date 17:18:50 * @ version 1.0 */header ("Content-type: text/html; charset = UTF-8 "); class C {static $ name = "static variable"; static public function stc_pc () {echo 'static public method <br> '; self: stc_pd (); self :: stc_pe (); self: stc (); // self: func (); // error reported but result} static protected function stc_pd () {echo 'static protected method <br> ';} static private function stc_pe () {echo 'static protected method <br>';} static function stc () {echo 'static normal method <br> ';} function func () {echo 'normal method <br>';} C: stc_pc (); /***** self: functionNmae (); it must be a static method (either in three modes )******/

 

3. Access the parent class through subclass (parent: functionNmae () and instantiate)

Conclusion:

Parent: functionNmae (); private cannot be accessed
$ Obj-> functionNmae (); private cannot be accessed

<? Php/*** @ authors HG (hg0728@qq.com) * @ date 17:18:50 * @ version 1.0 */header ("Content-type: text/html; charset = UTF-8 "); include '/class_a.php'; class B extends A {static public function index () {parent: stc_pc (); parent: stc (); parent: stc_pd (); parent: $ name; // No error // parent: stc_pe (); // inaccessible echo '<br> access through instantiation <br>'; $ a = new A (); $ a-> stc_pc (); $ a-> stc (); $ a-> stc_pd (); $ a-> $ name; // error // $ a-> stc_pe (); // not allowed} B: index ();/****** In the subclass, use: parent: functionNmae (); private: $ obj-> functionNmae (); private ******/