protected

问题 I know, there are no \'real\' private/protected methods in Python. This approach isn\'t meant to hide anything; I just want to understand what Python does. class Parent(object): def _protected(self): pass def __private(self): pass class Child(Parent): def foo(self): self._protected() # This works def bar(self): self.__private() # This doesn\'t work, I get a AttributeError: # \'Child\' object has no attribute \'_Child__private\' So, does this behaviour mean, that \'protected\' methods will be

问题 What is the reason that in Java, a member with a \"protected\" modifier can not only be accessed by the same class and by subclasses, but also by everyone in the same package? I am wondering about language design reasons, not actual applications (e.g., testing) 回答1: This design is based on the idea that the package is the appropriate unit, maintained and released by one internally consistent team; inheritance relationships have much less to do with who's maintaining and releasing what when.

问题 I have a object having some protected property that I want to get and set. The object looks like Fields_Form_Element_Location Object ( [helper] => formText [_allowEmpty:protected] => 1 [_autoInsertNotEmptyValidator:protected] => 1 [_belongsTo:protected] => [_description:protected] => [_disableLoadDefaultDecorators:protected] => [_errorMessages:protected] => Array ( ) [_errors:protected] => Array ( ) [_isErrorForced:protected] => [_label:protected] => Current City [_value:protected] => 93399

问题 I have a class called A in package1 and another class called C in package2. Class C extends class A. A has an instance variable which is declared like this: protected int protectedInt = 1; Here is the code for class A package package1; public class A { public int publicInt = 1; private int privateInt = 1; int defaultInt = 1; protected int protectedInt = 1; } And here is the code for class C: package package2; import package1.A; public class C extends A{ public void go(){ //remember the import

问题 I am confused about the meaning of access modifiers with respect to inheritance. What is the difference between inheritance involving the private , protected and public keywords? 回答1: what are Access Specifiers? There are 3 access specifiers for a class/struct/Union in C++. These access specifiers define how the members of the class can be accessed. Of course, any member of a class is accessible within that class(Inside any member function of that same class). Moving ahead to type of access

问题 When and why should I use public , private , and protected functions and variables inside a class? What is the difference between them? Examples: // Public public $variable; public function doSomething() { // ... } // Private private $variable; private function doSomething() { // ... } // Protected protected $variable; protected function doSomething() { // ... } 回答1: You use: public scope to make that property/method available from anywhere, other classes and instances of the object. private

问题 In Java, are there clear rules on when to use each of access modifiers, namely the default (package private), public , protected and private , while making class and interface and dealing with inheritance? 回答1: The official tutorial may be of some use to you. ______________________________________________________________ | │ Class │ Package │ Subclass │ Subclass │ World | | │ │ │(same pkg)│(diff pkg)│ | |───────────┼───────┼─────────┼──────────┼──────────┼────────| |public │ + │ + │ + │ + │ +