constructor calling in inheritance

Best Use of C# Constructors In Inheritance [How To]


//We have two classes, one is ClassA and other is ClassB, the ClassB inherit base class ClassA.
//If we make the object of child class ClassB then which class constructor called first?
namespace ConsoleNamespace
{
    class ClassA
    {
        public ClassA()
        {
            Console.WriteLine("ClassA::Constructor()");
        }
    }
    class ClassB : ClassA
    {
        public ClassB()
        {
            Console.WriteLine("ClassB::Constructor()");
        }
    }
    class Test
    {
        static void Main(string[] args)
        {
            ClassB a = new ClassB();
            Console.ReadLine();
        }
    }
}

The output is base class "ClassA" constructor called first. i.e. (ClassA::Constructor())



Example 2
//If child constructor is missing the parent constructor is called.
namespace ConsoleNamespace
{
    class ClassA
    {
        public ClassA()
        {
            Console.WriteLine("ClassA::Constructor()");
        }
    }
    class ClassB : ClassA
    {

    }
    class Test
    {
        static void Main(string[] args)
        {
            ClassB a = new ClassB();
            Console.ReadLine();
        }
    }
}

OutPut: ClassA::Constructor()

Example 3
//If parent constructor is missing the child constructor is called.
namespace ConsoleNamespace
{
    class ClassA
    {

    }
    class ClassB : ClassA
    {
        public ClassB()
        {
            Console.WriteLine("ClassB::Constructor()");
        }
    }
    class Test
    {
        static void Main(string[] args)
        {
            ClassB a = new ClassB();
            Console.ReadLine();
        }
    }
}


Output : ClassB::Constructor()


ANIL SINGH

Hey! I'm Anil Singh. I author this blog. I'm Active Blogger, Programmer. I love learning new technologies, programming, blogging and participating the forum discussions more...
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