Why is the Object class's clone() method giving a deep copy of object?

Question

As per the JAVA documentation, the super.clone() when called returns a shallow copy of the object. In the code below I have two objects name and id

Answer 1

Let's look at a section from your example: obj.id = new Integer(4);. Here you're not changing the internal representation of id - you're assigning new instance to the id reference. Both Integer and String are immutable so it's hard to feel the difference of shallow vs deep copy with them. Try to add e.g. an ArrayList attribute and in order to modify it you can e.g. add a new element obj.myList.add(13);