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Sadashiv Borkar
Ranch Hand

Joined: Jun 07, 2000
Posts: 49
hi guys,
I got this question in one of the mock exams..
public class NanTest
public static void main(String[] args)
Double d1 = new Double(Double.NaN);
Double d2 = new Double(Double.NaN);
if(Double.NaN == Double.NaN)
System.out.println("Nan is True");
System.out.println("Nan is False");

System.out.println("Nan Objects are True");
System.out.println("Nan Objects are False");
A)Nan is True Nan Objects are True
B)Nan is True Nan Objects are False
C)Nan is False Nan Objects are True
D)Nan is False Nan Objects are False
It asked what will be the output The answer comes as ( C ).
But according to me the answer should be ( D ) as NaN is not a number so it should be false in both the cases.
Can anyone tell me what is the reason behind the ( C ) answer .
Thanks in advance.....

Ranch Hand

Joined: Nov 22, 2008
Posts: 18944
the api states this in this regard
If d1 and d2 both represent Double.NaN, then the equals method returns true, even though Double.NaN==Double.NaN has the value false.
I agree. Here's the link:
subject: NAN
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