Doubt with ==

[Gitesh Ramchandani]

Given:
1. public class Foo {
2. private int val;
3. public foo(int v) (val = v }
4. public static void main (String [] args) {
5. Foo a = new Foo (10);
6. Foo b = new Foo (10);
7. Foo c = a;
8. int d = 10;
9. double e = 10.0;
10. }
11. }
Which three logical expressions evaluate to true? (Choose Three)
A. (a ==c)
B. (d ==e)
C. (b ==d)
D. (a ==b)
E. (b ==c)
F. (d ==10.0)
Ans: A,B,F

Doubt How B is correct, as it involves a double value? Also does it takes only the non-fractional part for comparison?

pls help
regards,
gitesh

[Henry Wong]

Originally posted by Gitesh Ramchandani:

Doubt How B is correct, as it involves a double value? Also does it takes only the non-fractional part for comparison?

No... when a int is compared with a double, the int is cast to a double for the comparison. Since, a value of 10, cast to a value of 10.0 without any lost of precision, the comparison is 10.0 to 10.0, which should be equal.

And please Quote Your Sources.

Thanks,
Henry

[raghu nagabandi]

when you compare numeric values internally it will promotes lower to higher version.
0==0.0
in this case 0 is converted into double as 0.0
then the compiler will perform comaprision.

[Gitesh Ramchandani]

thanks for help.