The answer is, as always, “it depends”. It depends on how big the returned collection will be. It depends on whether the result changes over time, and how important consistency of the returned result is. And it depends very much on how the user is likely to use the answer. First, note that you can … Read more
You could return an Integer instead of an int, returning null on parse failure. It’s a shame Java doesn’t provide a way of doing this without there being an exception thrown internally though – you can hide the exception (by catching it and returning null), but it could still be a performance issue if you’re … Read more
Go to the source! Grady Booch says (in Object Oriented Analysis and Design, page 49, second edition): Abstraction and encapsulation are complementary concepts: abstraction focuses on the observable behavior of an object… encapsulation focuses upon the implementation that gives rise to this behavior… encapsulation is most often achieved through information hiding, which is the process … Read more
If the class contains any template member functions you can specialize that member function to suit your needs. Even if the original developer didn’t think of it. safe.h class safe { int money; public: safe() : money(1000000) { } template <typename T> void backdoor() { // Do some stuff. } }; main.cpp: #include <safe.h> #include … Read more
Most answers here focus on OOP but encapsulation begins much earlier: Every function is an encapsulation; in pseudocode: point x = { 1, 4 } point y = { 23, 42 } numeric d = distance(x, y) Here, distance encapsulates the calculation of the (Euclidean) distance between two points in a plane: it hides implementation … Read more
You can create a new struct similar to the Ref<‘a,T> guard returned by RefCell::borrow(), in order to wrap this Ref and avoid having it going out of scope, like this: use std::cell::Ref; struct FooGuard<‘a> { guard: Ref<‘a, MutableInterior>, } then, you can implement the Deref trait for it, so that it can be used as … Read more
Firstly (IMO) don’t listen to people who say friend is not useful. It IS useful. In many situations you will have objects with data or functionality that are not intended to be publicly available. This is particularly true of large codebases with many authors who may only be superficially familiar with different areas. There ARE … Read more
The name scrambling is used to ensure that subclasses don’t accidentally override the private methods and attributes of their superclasses. It’s not designed to prevent deliberate access from outside. For example: >>> class Foo(object): … def __init__(self): … self.__baz = 42 … def foo(self): … print self.__baz … >>> class Bar(Foo): … def __init__(self): … … Read more
class A { public: int x; protected: int y; private: int z; }; class B : public A { // x is public // y is protected // z is not accessible from B }; class C : protected A { // x is protected // y is protected // z is not accessible from … Read more
A public member isn’t global if it isn’t also static, for access to a (non static) public member you need to create an object of that class so that don’t break the concept of encapsulation.