Constructor and Destructor – C# Programming Questions – Real

Q- Write constructors of class A and Class B to initialize class A’s variable int a, when we create the derived class object i.e. object B ob = new B(5); in main().

class A
{
    int a;

    // write class A constructor 


}
class B : A
{
    //write class B constructor
}

class Program
{
    static void Main(string[] args)
    {
        B ob = new B(5);
    }
}

Answer: Complete program below with comments. We have to use “base” keyword in derived class constructor to pass data to base class constructor via derived class constructor.

class A
{
    int a;
    public A(int j)
    {
        a = j;
    }
}
class B : A
{
    //use "base" keyword to pass the value to clas A constructor.
    public B(int j): base(j)
    {
    }
}

class Program
{
    static void Main(string[] args)
    {
        //pass int value 10 to initialize
        //base class A variable int a;  
        B b = new B(5);

    }
}