K&B page398

[Cathy Song]

  
1. public class ObjComp {
2. public static void main(String [] args ) {
3. int result = 0;
4. ObjComp oc = new ObjComp();
5. Object o = oc;
6.
7. if (o == oc) result = 1;
8. if (o != oc) result = result + 10;
9. if (o.equals(oc) ) result = result + 100;
10. if (oc.equals(o) ) result = result + 1000;
11.
12. System.out.println("result = " + result);
13. }
14. }

Result: 1101
Can someone please explain how line 9,10 are true?
Thanks.

[Cathy Song]

I found the answer in the API

The equals method for class Object implements the most discriminating possible equivalence relation on objects; that is, for any non-null reference values x and y, this method returns true if and only if x and y refer to the same object (x == y has the value true).

Thanks