It (along with the this keyword) is instructing the constructor to call another constructor within the same type before it, itself executes. Therefore: public ListNode(object dataValue) : this(dataValue, null) { } effectively becomes: public ListNode(object dataValue) { data = dataValue; next = null; } Note that you can use base instead of this to instruct … Read more
I see two reasons your original set of declarations shouldn’t compile cleanly: There should be a warning in TCellPhone that its constructor hides the method of the base class. This is because the base-class method is virtual, and the compiler worries that you’re introducing a new method with the same name without overriding the base-class … Read more
No, there is no way to do this. According to the language specs, instance variables aren’t even initialized until a super() call has been made. These are the steps performed during the constructor step of class instance creation, taken from the link: Assign the arguments for the constructor to newly created parameter variables for this … Read more
C++11 allows constructor chaining (partially). This feature is called “delegating constructors”. So in C++11 you can do the following class Foo { public: Foo(int a) : Foo() { _a = a; } Foo(char* b) : Foo() { _b = b; } Foo() { _c = 1.5; } private: int _a = 0; char* _b = … Read more
The order is: Member variables are initialized to default values for all classes in the hierarchy Then starting with the most derived class: Variable initializers are executed for the most-derived type Constructor chaining works out which base class constructor is going to be called The base class is initialized (recurse all of this 🙂 The … Read more
You use standard syntax (using this like a method) to pick the overload, inside the class: class Foo { private int id; private string name; public Foo() : this(0, “”) { } public Foo(int id, string name) { this.id = id; this.name = name; } public Foo(int id) : this(id, “”) { } public Foo(string … Read more