PHP Magic Method __get () and __set () understanding

The __get () method, which is explained in the official manual, is called when a class property or method that is not defined or is not visible in the current environment is invoked (by adding: or Setting | assignment). these undefined or invisible class properties or methods are addressed by using the inaccessible properties and the inaccessible methods (inaccessible methods) later in this section. ' Undefined ' is easy to understand. We know that class permission control has three keywords ' public ', ' private ', ' protected ', which are not visible except ' public ' for __get () and __set () methods, when access and settings are undefined and defined but the keyword is ' Private,protected ' property automatically calls the __get (), __set () method.

Normally __get () returns the value of the second argument value by default, and __set () returns the value of the first parameter name by default (note: There is a bit of ambiguity here, which says that PHP ignores the return value of __set (), which means that the __set () is ignored. The custom return value in the method body returns the default return value as usual, that is, the __set () method returns the default return value anyway, and __get () does not ignore any return value, and when the method body has a return value returned, no return value returns the default return value.

And the point of note is:

Because of how PHP handles assignment operations,the return value of __set () is ignored . Similarly, in the chain assignment below, __get () is not called :

$a = $obj->b = 8; ( this notation __get () will not be called, although it seems to access a non-existent property B, assigning a property to a variable is also a condition of accessing an attribute )

PHP Magic Method __get () and __set () understanding