Writing a function to that sorts any object

Question

I am trying to write a function that sorts any type of array of objects. For example, I want to call
NewArray = exampleclass.sort(ObjectOfAnyType).
The sort function has to return a new array. I have run into two errors, however.
Error #1
as3.java [21:1] cannot resolve symbol
symbol : variable Object
location: class as3
if (Object instanceof Comparable)
^
Error #2
as3.java [25:1] incompatible types
found : java.lang.Object
required: java.lang.Object[]
Object [] rtn = obj.clone();
*** Below is my source code ***
import java.*;
public class as3 {
/** Creates new as3 */
public static Object sort(Object [] obj)
     if (Object instanceof Comparable)
     if (Object instanceof Cloneable)
     Object [] rtn = obj.clone();
for (int i = 0; i<obj.length-1; i++)
for (int j=i+1; j<obj.length; j++)
if (rtn.compareTo(rtn[j]) == 1)
Object [] tmp = rtn[i];
rtn[i] = obj[j];
rtn[j] = tmp;
else
throw new ObjectIsNotComparableException("Object not comparable");
Any help appreciated. Thanks!

Answer 1

Changing from "Object" to the name "obj" fixed the
statement:
if (obj instanceof Cloneable) but not if (obj
instanceof Comparable).
I don't know what's causing this one yet... worry about that in a sec
I am also getting one new error now:
as3.java [28:1] cannot resolve symbol
symbol : method compareTo (java.lang.Object)
location: class java.lang.Object
if (rtn[ i].compareTo(rtn[j])
This one is because rtn[ i] (and rtn[j]) is an Object, which has no method compareTo. Try casting it to a Comparable...
I think I just worked out why it let you go with the cloneable, but not with the comparable. obj is an array, and sure an array is cloneable, but how could you compare an array? Sure you can compare the elements in the array... So either check if obj[0] instanceof Comparable, or drop the test all together.
Note: checking obj[0] will give you an exception if someone asks you to sort an array of 0 length (no elements)
Hope this helps,
Radish21