It’s wrong to say that a compiler-generated default constructor takes no action. It is equivalent to a user-defined constructor with an empty body and an empty initializer list, but that doesn’t mean it takes no action. Here is what it does: It calls the base class’es default constructor. It initializes the vtable pointer, if the … Read more
If you define a class without any constructor, the compiler will synthesize a constructor for you (and that will be a default constructor — i.e., one that doesn’t require any arguments). If, however, you do define a constructor, (even if it does take one or more arguments) the compiler will not synthesize a constructor for you — at that … Read more
Neither of them. If you define it, it’s not the default. The default constructor is the no-argument constructor automatically generated unless you define another constructor. Any uninitialised fields will be set to their default values. For your example, it would look like this assuming that the types are String, int and int, and that the … Read more