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Simple question

ji soi

Joined: Jun 14, 2005
Posts: 13
System.out.println(Math.min(-0.0,+0.0) == Math.max(0.0,+0.0));
6: }

returns true.

can anyone explain me how ?
Corey McGlone
Ranch Hand

Joined: Dec 20, 2001
Posts: 3271
If you check out the Float API Spec, you'll see this under the description of the equals method:

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.

[ June 20, 2005: Message edited by: Corey McGlone ]

SCJP Tipline, etc.
marc weber

Joined: Aug 31, 2004
Posts: 11343

Also note this post...

"We're kind of on the level of crossword puzzle writers... And no one ever goes to them and gives them an award." ~Joe Strummer
ji soi

Joined: Jun 14, 2005
Posts: 13
Thanks for ur clarification.

One more question

public First (String s) {




public class Second extends First {

public static void main(String args []) {

new Second();



This program gives error " No constructor matching found in class first"

If i add empty constructor first()
it works.

I read in a book
Even if there is no constructor default const. will added by the compiler without no parameters.
then why is this error.

plz help me with this
marc weber

Joined: Aug 31, 2004
Posts: 11343

The compiler will provide a no-args constructor only if no other constructors are specified. If you specify any constructor (arguments or not), then the compiler will not add one.
[ June 20, 2005: Message edited by: marc weber ]
I agree. Here's the link:
subject: Simple question
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