Describes how to use php magic methods _ get () and _ set ()

Php magic methods _ get () and _ set () are introduced. if you need them, refer to the instructions in the official php documentation:
_ Set () is run when writing data to inaccessible properties.
_ Get () is utilized for reading data from inaccessible properties.

How can I translate data in Chinese?
Inaccessible: n. hard to achieve; hard to close; ununderstandable.

Code has the truth:

The code is as follows:

Error_reporting (E_ALL );
Class stu {
Private $;
Private $ B = 0;
Public $ c;
Public $ d = 0;
// Private can be replaced by protected public.
Private function _ get ($ name ){
Return 123;
}

// Private can also be replaced by protected public.
Private function _ set ($ name, $ value ){
Echo "This is set function ";
}
}
$ S = new stu ();
Var_dump ($ s-> a); // output: 123
Var_dump ($ s-> B); // output: 123
Var_dump ($ s-> c); // output: null
Var_dump ($ s-> d); // output: 0
Var_dump ($ s-> e); // output: 123
$ S-> a = 3; // output: This is set function
$ S-> c = 3; // no output
$ S-> f = 3; // output: This is set function
?>

Result analysis:
If the _ get method is not available, executing var_dump ($ s-> a) var_dump ($ s-> B) will cause a fatal error.
If the _ get method is not available, a notice will be generated when var_dump ($ s-> e) is executed, prompting that no attribute is defined. $ e

Summary:
1. when reading data from an inaccessible attribute, the _ get () method is called.
2. when assigning values to an inaccessible attribute, the _ set () method is called.
3. difficult to access include: (1) private attributes; (2) uninitialized attributes
4. _ isset () _ unset () is similar.