What does the object creation statement in java exactly means?

Question

Assuming X and Y both class.What does below statements means?

X obj1 = new X();
X obj2 = new Y();

Whose reference and whose memori will be given in above case? please elaborate!

score 2 · Answer 1 · answered Oct 13 '14 at 18:26

2

This creates an object of type X and assigns a reference to it to a variable called obj1.

It then creates another object, this time of of type Y, and assigns a reference to it to a variable called obj2.

For the second line to compile, Y has to be a subclass of X.

answered Oct 13 '14 at 18:26

NPE

I still didn't get you...What does object of type Y means in sense of memory and reference? – Niyat patel Oct 13 '14 at 18:35
@Niyatpatel: Does this help http://stackoverflow.com/questions/9224517/what-is-a-class-reference-and-an-object? – NPE Oct 13 '14 at 18:37

score 0 · Answer 2 · answered Oct 13 '14 at 18:27

X is just a handler. The actual object creation is defined by the new statement. So

X obj1 = new X();  // ---> Will create an X() object 
X obj2 = new Y();  // ---> Will create an Y() object

In each case they reference a separate location in the memory. In other words, obj1 != obj2

2 Answers2