Shallow Copying And Deep copying ?

[Angela Narain]

Can someone explain to me shallow copying and deep copying
with an example ..
Thanks

[Thomas Paul]

<font size="+0">
    Vector v1 = new Vector();
    v1.add(new Button("1"));
    v1.add(new Button("2"));
    v1.add(new Button("3"));
// I now have a Vector with 3 Button objects in it.
    Vector v2 = (Vector)v1.clone();
// v2 is now a copy of v1 BUT both Vectors still point to the 
// same objects - we have made a shallow copy
    Button b1 = (Button)v1.get(0);
    b1.setLabel("4");
    Button b2 = (Button)v2.get(0);
    System.out.println(b2.getLabel()); // will print "4"

A shallow copy makes a copy of the container but does not make a copy of the objects within the container. The API describes it as clone() makes a copy of the internal array but not the elements within the array.
A deep copy would make a copy of each element with the Vector as well as the Vector itself. clone() does not support this functionality.

[kanchan chaudhary]

Hi,
Where can I find the Constructors & methods of Vector class?
Thanks
kanchan

[Junilu Lacar]

http://java.sun.com/j2se/1.3/docs/api/index.html