...two float values are considered to be the same if and only if the method floatToIntBits(float) returns the identical int value when applied to each.

Note that in most cases, for two instances of class Float, f1 and f2, the value of f1.equals(f2) is true if and only if

f1.floatValue() == f2.floatValue()

also has the value true. However, there are two exceptions:

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.

This definition allows hash tables to operate properly.

--Float.equals() Java doc