//We can create the constructor of abstract class, but we cannot create the constructor of interface why?

Constructor are mainly used to initialized the instance variable, inside abstract class instance variable are final or non-final  (so we can create constructor of abstract class) and inside interface all instance variable are by default final(so we cannot create the constructor of interface because  final variable are initialized at the time of declaration)

abstract public class PrintName {

               

                String fname;

                String mname;

               

                public PrintName()

                {

                                super();

                }

               

public PrintName(String fname, String mname) {

                                super();

                                this.fname = fname;

                                this.mname = mname;

                }

abstract public void printingFullName();

}

public class PrintNameBase extends PrintName {

            String lname;

public PrintNameBase(String lname) {

                        super("govind","ballabh");

                        this.lname = lname;

            }

           

            @Override

            public void printingFullName() {

              System.out.println("FullName="+fname+" "+mname+" "+lname);

            }

            public static void main(String[] args) {

                        PrintNameBase pnb=new PrintNameBase("khan");

                        pnb.printingFullName();

            }

}

o/p:-------------

FullName=govind ballabh khan

public interface PrintNameInterface {

             String fname="govind";

             String mname="ballabh";

             String lname="khan";

             public void printName();

}

public class Printbase implements PrintNameInterface {

@Override

            public void printName() {

                        System.out.println("Full Name="+fname+" "+mname+" "+lname);

                       

            }

           

            public static void main(String[] args) {

                        Printbase pb=new Printbase();

                        pb.printName();

            }

}

FullName=govind ballabh khan