php class knowledge --- constant drip

• Constants in the class of internal and external can be accessed through the class name :: constant names
• Constant no access modifier
• The difference is variable, not a constant value in double quotes, and the variable can

<? PHP 
class mycoach 
{ 
    public $ name = "Chen Peichang"; 
    CONST = 22 is hisage; 
    public $ Age = 22 is; 
    Private Favorite $ = "favorite cauldron D"; 
    public the __construct function () 
    { 
        echo $ this-> name. " Christina ".mycoach :: hisage $ this-> favorite.PHP_EOL;. 
        echo" constants can not be enclosed in double quotes values: ------- Chen Peichang brother :: hisage Christina mycoach ".PHP_EOL; 
        echo" variable value may be in double quotes: ------- Chen Peichang brother Christina this- $> Age ".PHP_EOL; 
    } 
    public function the __get (Key $) 
    { 
        return the this $ -> $ Key; 
    } 
    public function the __set ( Key $, $ value) 
    { 
        $ the this -> Key $ = $ value; 
    } 
} 
$ mycoach new new CPC = ();
?>

Output:

Christina Chen Peichang like 22 Ding cauldron
constant values can not be enclosed in double quotes: ------- brother Chen Peichang Christina mycoach :: hisage
variables can be enclosed in double quotes values: ------- Chen Peichang Christina brother 22