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casting

sonali saxena
Greenhorn

Joined: Mar 18, 2001
Posts: 16
class Parent {}
class DerivedOne extends Parent {}
class DerivedTwo extends Parent {}


Which of the following statements is correct for the following expression?
Parent p = new Parent();
DerivedOne d1 = new DerivedOne();
DerivedTwo d2 = new DerivedTwo();
d2 = d1;



A. Illegal both at compile and runtime.
B. Legal at compile time, but may fail at runtime.
C. Legal at both compile and runtime.
The answer given is 'b' but according to me it is 'a'. Am I wrong?
Thanx
Sonali
Tejas Kansara
Ranch Hand

Joined: Dec 14, 2000
Posts: 38
According to me it is 'a'
bcoz you cannot type cast one derived to other derived instead you can cast from derived to base class.
Cheers
Tejas Kansara
Umesh Joglekar
Greenhorn

Joined: May 02, 2001
Posts: 16
A is correct. It will not compile. It will also not compile with an explicit cast i.e. d2 = (DerivedTwo) d1 because d1 is not convertible to d2 even with a cast.
 
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subject: casting