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float equality

Mert Caliskan

Joined: May 08, 2007
Posts: 10

why is this outputs false?
Joan Horta Tosas
Ranch Hand

Joined: Feb 01, 2007
Posts: 59
Because f1 and f2 are two different objects. You have to use equals(). But note that using equals() would give false as well, due to IEEE 754 floating-point "single format" bit layout, as it says in Float.equals() there are two exceptions on having the same result on comparing two float objects and two float values:
� If f1 and f2 both represent Float.NaN, then the equals method returns true, even though Float.NaN==Float.NaN has the value false.
� If f1 represents +0.0f while f2 represents -0.0f, or vice versa, the equal test has the value false, even though 0.0f==-0.0f has the value true.

[ November 03, 2007: Message edited by: Joan Horta Tosas ]
Prasun Howlader
Ranch Hand

Joined: Oct 21, 2007
Posts: 89
I think in the wrapper class negative zero strictly smaller than positive zero.However, the methods Math.min and Math.max treat negative zero as beign smaller that positive zero.

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subject: float equality
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