Question

String child = "C";
Parent p = null;
try {
    Class c1 = new Class.forName(child);
    Constructor co = c1.getConstructor();
    // p=co.newInstance(null); //This gives compilatoin error cannot
    // conver object to Parent
    // p=(c1.getClass())co.newInstance(null);//also gives cast errror
    p = (Parent) co.newInstance(null);// this works but it typecasts the
    // child to Parent
} catch (Exception e) {
}

What am i trying to do.

I have multiple Child classes inherited from Parent. I am getting child class name as string input.

I want to instantiate the object of Child class and assign it to Parent. I do not want to type cast Child to Parent. As later in the code i need to compare two Child classes. If I typecast it to Parent. I cannot differentiate between Child1 and Child2.

Answer 1

Typecasting has absolutely no effect on the object itself. Using p = (Parent) t simply does a runtime check on t to make sure that the type of t is assignable to Parent (i.e. either t is-a Parent or it is-a subclass of Parent) . Afterward, t will still be a Child1 or whatever its actual type always has been.

Use the explicit cast.