Sequence of constructor call

Question

Suppose we have class-Class A & Class B

Class A Have one Default Constructor & One Paramatrized constructor

Class B Have one Default Constructor & One Paramatrized constructor

If we create the Object of B...What will be the sequence of constructor call..

Kindly Tell Me..

Thanks!!

Abhineet Srivastava · Answer

OK.. Got it.. Thank you very much!!

Vulpes · Answer

In that case, it simply won't compile,. The error you'll get is: Cannot implicitly convert type 'B' to 'A'

Abhineet Srivastava · Answer

No Vupas... I m saying that what will happen when b Don't inherit class A & We are creating objest like A a =new B();

Vulpes · Answer

If the code is like this: using System; class A { public A() { Console.WriteLine("Hi"); } } class B : A { public B() { Console.WriteLine("Bye"); } } class Test { static void Main() { A a = new B(); } } then the output will be: Hi Bye As before A's constructor will run first, followed by B's constructor. The fact that you're creating an object of type B and assigning a reference to it to a variable of type A makes no difference to the constructor logic.

Abhineet Srivastava · Answer

one more question to clear vulps- suppose our code is like that- Class a { C.w("Hi") } class B { c.w("Bye") } Class Test { A a = New B(); } Then what will output?

Abhineet Srivastava · Answer

Thanks Mate :) Now,Its has been clear for me

Vulpes · Answer

Here's some example code which illustrates my previous reply: using System; class A { public A() { Console.WriteLine("A's default constructor called"); } public A(int i) { Console.WriteLine("A's parameterized constructor called - {0} passed", i); } } class B : A { public B() { Console.WriteLine("B's default constructor called"); } public B(int i) : base(i) { Console.WriteLine("B's parameterized constructor called - {0} passed", i); } } class Test { static void Main() { B b = new B(); Console.WriteLine(); B b2 = new B(3); Console.ReadKey(); } } The output is: A's default constructor called B's default constructor called A's parameterized constructor called - 3 passed B's parameterized constructor called - 3 passed

Vulpes · Answer

The code within the constructors will execute in the following order: System.Object's default constructor (does nothing). A's constructor. This will be the default constructor unless the parameterized one is specified using the 'base' keyword. B's default constructor if no arguments are specified when creating the B object, otherwise B's parameterized constructor.

Abhineet Srivastava · Answer

Class B inherit Class A

Prashant Yadav · Answer

What is the relationship between Class A and Class B ? Create one console app do onsole write in constructor and see your self

Sequence of constructor call

Answers (10)