Issue on abstract class.

Rampradeep kalivarapu

11y213Java

i am not getting the problem where it has getting wrong.In my code i am able to create instance for abstract class.please give any help.

abstract class abstractclass

{

public abstract void method();

}

public abstract class abstractclass1 extends abstractclass

{

public static void main(String[] args) {

abstractclass1 o=new abstractclass1() {

@Override

public void method() {

// TODO Auto-generated method stub

System.out.println("abstract method is implemented....");

}

};

o.method();

}

13 Replies

Know the answer? Post it — somebody with the same question will find it here.

Nishant Mittal10y ago
Hope this will help you

http://stackoverflow.com/questions/13670991/interview-can-we-instantiate-abstract-class
0
Rampradeep kalivarapu10y ago
To power

just make abstract1class as abstract by using 'abstract' keyword.Then try to create instance of it.
0
Ranjit Powar10y ago
If it is Java then you have to extend parent class

public class abstractclass1 extend abstractclass
0
Nishant Mittal10y ago
if you will not make it public.. you will get following error during compilation in .Net

Error 1 Inconsistent accessibility: base class 'practice.abstractclass' is less accessible than class
0
Rampradeep kalivarapu10y ago
Hai power i know that we can not create instance for the abstract class and interfaces.But we can make assign reference variables to child class objects.

But here i am able create instance for abstract class and why and how this is happening.Is it some other concept in java please let me know if anyone knows.
0
Ranjit Powar10y ago
This is your code
public abstract class abstractclass1 : abstractclass

You are making both classes. Change it

public class abstractclass1 : abstractclass
0
Nishant Mittal10y ago
Sorry but I am not aware of that..But concepts will remain same for all language.

I will check in java as well give me some time..
0
Rampradeep kalivarapu10y ago
this all happening in java 1.8 version.
0
Nishant Mittal10y ago
Hi,

I have tried your code in C#

and c what I got , error message I cant create as instance of Abstract Class.Screen shot is attached for your referecne. And also find below my code

public abstract class abstractclass
{
public abstract void method();
public void HelloWorld()
{
Console.WriteLine("Hello World");
}
}
public abstract class abstractclass1 : abstractclass
{
public static void main(String[] args)
{
abstractclass1 o = new abstractclass1();
o.method();
o.HelloWorld();
}
//@Override
//public void method()
//{
// // TODO Auto-generated method stub
// Console.WriteLine("abstract method is implemented....");
//}
//o.method();
public override void method()
{
throw new NotImplementedException();
}
}
Cheers
0
Nishant Mittal10y ago
Hi,

Here is the problem

Constructors on abstract types can be called only by derived types. Because public constructors create instances of a type, and you cannot create instances of an abstract type, an abstract type that has a public constructor is incorrectly designed.

Check this out for more details..

https://msdn.microsoft.com/en-us/library/ms182126.aspx
0
Rampradeep kalivarapu10y ago
even i make child class as abstract also i am able to create instance thats what i am not understandiing.
0
Ranjit Powar11y ago
You can't create object of abstract class. So don't make child class abstract.
0
Ravi Patel11y ago
Hi ,
problem is you are trying to create the object of abstract class
you can not create the object of abstract class .

abstract class abstractclass
{
public abstract void method();
}
public class abstractclass1 extends abstractclass
{
public static void main(String[] args) {
abstractclass1 o=new abstractclass1() {
@Override
public void method() {
// TODO Auto-generated method stub
System.out.println("abstract method is implemented....");
}
};
o.method();
}
}

try this code
0