definition

When we design classes in Java, Vala, or C# we put the definition and declaration in the same source file. But in C++ it is traditionally preferred to separate the definition and declaration in two or more files. What happens if I just use a header file and put everything into it, like Java? Is there a performance penalty or something? The answer depends on what kind of class you're creating. C++'s compilation model dates back to the days of C, and so its method of importing data from one source file into another is comparatively primitive. The #include directive literally copies the contents

The Open/Closed Principle states that software entities (classes, modules, etc.) should be open for extension, but closed for modification. What does this mean, and why is it an important principle of good object-oriented design? Specifically, it is about a "Holy Grail" of design in OOP of making an entity extensible enough (through its individual design or through its participation in the architecture) to support future unforseen changes without rewriting its code (and sometimes even without re-compiling **). Some ways to do this include Polymorphism/Inheritance, Composition, Inversion of

Could someone explain the difference between Software Design and Software Architecture? More specifically; if you tell someone to present you the 'design' - what would you expect them to present? Same goes for 'architecture'. My current understanding is: Design: UML diagram/flow chart/simple wireframes (for UI) for a specific module/part of the system Architecture: component diagram (showing how the different modules of the system communicates with each other and other systems), what language is to be used, patterns...? Correct me if I'm wrong. I have referred Wikipedia has articles on http:/

Most C++ programmers like me have made the following mistake at some point: class C { /*...*/ }; int main() { C c(); // declares a function c taking no arguments returning a C, // not, as intended by most, an object c of type C initialized // using the default constructor. c.foo(); // compiler complains here. //... } Now while the error is pretty obvious once you know it I was wondering if there is any sensible use for this kind of local function declaration except that you can do it -- especially since there is no way to define such a local function in the same block; you have to define it