CompuServe Messages

Simple case: class Window { private: char *name; short xpos, ypos, xwid, ywid ; … public: Window() ; Window(char *s); ~Window(); void MoveWindow(short newx, newy); } Window::Window() { if (necessary-libs-not-open) open_the_necessary_libs; xpos = ypos = 0; name = "Default Window" ; xwid = ywid = 50; } Window::Window(char *s) { xpos = ypos = 0; name = new char [strlen(s)+1]; strcpy(name, s); xwid = ywid = 50; } Window::~Window() { delete name; if (I am the last Window) close_the_libraries_and_release_the_memory; } … main() { Window a; } Simply declaring variable a to be of type Window causes the compiler to do everything you specified in your "constructor." In this case, two different constructors were defined, one for default windows, one for named windows. The compiler sees "Window a" and uses the default constructor. If you had written "Window a("Showing Off")" you'd get the named constructor. Once the variable passes out of scope, the compiler calls all the cleanup code in your "destructor," named by convention as ~<class being destroyed>. In complex environments such as Intuition where there's a lot of preliminary and a lot of cleanup, this is a keystroke-saver. By the way, there are at least a half dozen bugs in the example code, but you get the idea.