protected

so I'm trying to work out an issue I'm having in designing PHP classes. I've created a base class, and assigned private variables. I have child classes extending this base class, which make reference and changes to these private variables through functions of the base class. Here's an example, keep in mind I'm still confused about the difference between private and protected methods/variables (let me know if I'm doing it wrong!): base.class.php <?php class Base { private $test; public function __construct(){ require('sub.class.php'); $sub = new Sub; echo($this->getTest()); } public function

I was wondering whether it is possible to assign a value to an HTML text box and protect it. What I mean is make it´s content unmodifiable, so that when the form gets submitted im "sure" it was this value which was submitted. BTW I realize the easier way would be not to "listen" fot this input and just assign it but it would come in handy to be able to do what´s stated above. I hope the question is clear enough, please ask for any needed clarification. Thanks in advance! EDIT: I was definitely not clear enough but I tried to express that i should hold the value after submitted (not modifiable

#include <iostream> class A { protected: void foo() {} }; class B : public A { public: void bar() { std::cout << (&A::foo) << std::endl; } }; int main() { B b; b.bar(); } Here I am trying to get address of protected member function of base class. I am getting this error. main.cpp: In member function ‘void B::bar()’: main.cpp:5: error: ‘void A::foo()’ is protected main.cpp:13: error: within this context make: *** [all] Error 1 Changing foo to public works. Also printing &B::foo works. Can you please explain why we can't get address of protected member function of base class? B is allowed to

/*Child is inherited from Parent*/ class Parent { public: Parent () //Constructor { cout << "\n Parent constructor called\n" << endl; } protected: ~Parent() //Dtor { cout << "\n Parent destructor called\n" << endl; } }; class Child : public Parent { public: Child () //Ctor { cout << "\nChild constructor called\n" << endl; } ~Child() //dtor { cout << "\nChild destructor called\n" << endl; } }; int main () { Parent * p2 = new Child; delete p2; return 0; } If I make Parent 's destructor virtual, then I obtain an error, so what is the purpose of making a protected destructor virtual? Just to give

I have the following code: struct A { protected: A() {} A* a; }; struct B : A { protected: B() { b.a = &b; } A b; }; It strangely doesn't compile. The culprit is the b.a = &b; assignment: both GCC and clang complain that A() is protected, which shouldn't be a problem because B inherits A. Which dark corner of the standard have I come into? David Rodríguez - dribeas The meaning of protected is that the derived type will have access to that member of its own base and not of any random object * . In your case, you care trying to modify b 's member which is outside of your control (i.e. you can

I "learned" C++ at school, but there are several things I don't know, like where or what a compiler can optimize, seems I already know that inline and const can boost a little... If performance is an important thing (gaming programming for example), does putting class attributes not public ( private or protected ) allow the compiler to make more optimized code ? Because all my previous teacher were saying was it's more "secure" or "prevent not wanted or authorized class access/behavior", but in the end, I'm wonder if putting attributes not public can limit the scope and thus fasten things. I

This question already has an answer here: Pros and cons of package private classes in Java? 8 answers I love access control in any language, but I find that in Java I almost never (if ever) use the package-private access modifier (or lack thereof). I realize that inner classes can be private , protected , or package-private , but outer classes can only be package-private or public . Why can an outer class be package-private but not protected ? What is the benefit of restricting classes/methods/fields to be seen by the entire package, but not subclasses? I use package-private classes and

My question involves specifically Java, abstract classes, and the use of protected data. I am being told that all the data should be private, and protected getters/setters used only. Now, I understand we want to shield data from direct manipulation by casual users of the class, and that public data members in general are a questionable practice. I have looked at "Java protected fields vs public getters" ( Java protected fields vs public getters ), but I still am dubious that: protected int i; is worse in an abstract class than: private int i; protected int geti(); protected void seti(int j); I