You cannot. Your code has an undefined behavior. If I modify the main() function to: int main() { Person *p = new Person(); Developer* d = dynamic_cast<Developer*>(p); assert(d!=0); d->Pi(); delete p; delete d; return 0; } Then the assertion d!=0 is triggered. That shows that the dynamic_cast failed. You call Developer::Pi on a null pointer, … Read more
First of all, the code you posted is not valid Java. It is important that you post working code, otherwise we can’t be sure about what you are asking. Does the statement super(1,2,3) in the class B create a private fields same as the private fields in the class A? Or is it illegal to … Read more
Private variables are there to help with the work behind the scenes in a class, work that the creator doesn’t want you interfering in. Just because you can’t see or access the private variables, it doesn’t mean the compiler’s just going to throw them away. Perhaps it will make more sense to you in this … Read more
The way you have it written currently, class C would be deriving from A twice (once directly, and once indirectly from B) 5 solved Inheritance misfit
class Number : public string { public: Number() : string(“0”) { } Number(const string &str) : string(str) { } }; However, as long as you have the following 2 lines in the beginning, the name Number will be replaced by preprocessor. #ifndef Number #define Number You should use another macro name for the #include guard. … Read more
Make your Racer superclass abstract and include an abstract method called move. Then when you extend Racer to each of the racer types, you can write unique methods that all return a value indicating the distance to move. This enables you to create a list of racers and call the move method directly from the … Read more
Output will obviously correspond to System.out.println(“You are NOT welcome, “+name+”!”); having the subclass method is superclass will only allow your code to compile. i.e test.hello(“Tomáš”); after type cast. However at runtime method of Greeter_mean is called as the instance if really of type Greeter_mean. solved When I cast object to its supertype do I access … Read more
You create a new reception’s object on every cycle iteration. Try to put this definition before the cycle and use this object in the cycle. Also, you’ll need to write an empty constructor and getters/setters for values: reception add=new Reception(); do { … add.setNumerodehotel(x); add.setResidente1(name); } while (…) public abstract class Hotel { ArrayList<Integer> numerodehotel … Read more
Main m = new Main(); This code in class B will simply create an object of Main class. After this you need to call this to fill the arrayList. m.add() 1 solved Java Inheritance not working
I’m not entirely sure what you want to achieve, but to get it compile, simply add implicit constructor to class a: class a { public a(int x) { System.out.println(x); } public a() { // implicit constructor } } Since b extends a and doesn’t call the super constructor, implicit constructor of a is called “behind … Read more
To find out for yourself what is happening exactly, you could run your code in a debugger and step through it to see what happens step by step. This is what happens: When you create a new Derived object, the field value in the Base part is first initialized to 0. Then the constructor of … Read more
how to provide value to parent class constructor where parent constructor have more argument than child class from static void main in c#? [closed] solved how to provide value to parent class constructor where parent constructor have more argument than child class from static void main in c#? [closed]
As for your firs question: yes one can make a Python program without using classes or functions at all: all satements are executed in theorder they are encountered 2) you certainly are mixing some concepts there, but generally “yes” – one could stop a loop running in another method if running in parallell to that … Read more
Yes. Assuming the classes remain in the same package – x.getVal will work. class A { String getVal(){ return “from a”; } } class B extends A { } public class C { public static void main(String [] args) { B x = new B(); x.getVal(); } } It works – because of the default … Read more
Your PrintDetails() method is printing the array without any kind of formatting (hence it’s just printing the array type) use string.Join to print the array delimenated by commas public override void PrintDetails() { Console.WriteLine(“Hi my name is ” + _name + ” and I am studying ” + string.Join(“,”, _subjects)); } ought to do it. … Read more