Clone() method error

Question

When I compile the following program I get the "incompatible types error". Are not s1 and s2 of class Object?!
public class CloneApp {
     public static void main(String args[]) {
          CloneApp s1, s2;
          s1 = new CloneApp();
          s2 = s1.clone();
Thanks.

Answer 1

Furthermore, clone() throws an exception if the object's class does not implement Cloneable. Your code should look like
public class CloneApp implements Cloneable {
   public Object clone() {
      try {
         return super.clone();
      } catch(CloneNotSupportedException e) {
         throw new InternalError(e.toString());
   public static void main(String[] args) {
      CloneApp s1, s2;
      s1 = new CloneApp();
      s2 = (CloneApp) s1.clone();
}