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Groups > comp.lang.java.programmer > #36804

Re: How to assign an object to another in it method?

From Arne Vajhøj <arne@vajhoej.dk>
Newsgroups comp.lang.java.programmer
Subject Re: How to assign an object to another in it method?
Date 2017-07-04 21:46 -0400
Organization Aioe.org NNTP Server
Message-ID <ojhgd6$bjn$1@gioia.aioe.org> (permalink)
References (8 earlier) <ojd820$gl5$1@dont-email.me> <ojddsm$8df$1@gioia.aioe.org> <slrnolkjtk.o2q.avl@logic.at> <ojet3n$ek2$1@gioia.aioe.org> <ojf0vn$7d0$1@jstuckle.eternal-september.org>

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On 7/3/2017 11:15 PM, Jerry Stuckle wrote:
> On 7/3/2017 10:04 PM, Arne Vajhøj wrote:
>> On 7/3/2017 10:04 AM, Andreas Leitgeb wrote:
>>> Arne Vajhøj <arne@vajhoej.dk> wrote:
>>>> That is what I consider the missing default parameter issue.
>>>>         // **** NOT JAVA ****
>>>>         public Demo(String name, int answer = 6, boolean prisoner =
>>>> false)
>>>
>>> Imho this is one thing that Java actually got right, by *not* supporting.
>>>
>>> In C++, default values can give a hard time when overiding methods with
>>> defaults, as the default value depends on the static target object
>>> type even for virtual methods.
>>
>> Yes.
>>
>> But is that really a problem?
>>
>> It seems like what one would expect.
>>
>> And changing the default value when overriding should be
>> documented rather well as it is a somewhat suspicious
>> thing to do.
>>
>> I hope that a static code analysis tool create warnings
>> about doing something like that.
> 
> Why should they, Arne?  Default values are just that - values used when
> no others are given.  They are not the only valid values, and are there
> to be overridden.

It indicates that the author of the super class and the author of the
sub class seems to disagree on at least one aspect of how the method
should be. That is something that should always be examined. Do the
classes really reflect an "is a" relation or is the difference a
symptom of a bigger difference/problem.

On top of that comes the problem Andrea brought up where change
to variable type can change behavior due to default values
being non-polymorphic in nature.

But I am more concerned about the first issue. As the second
issue would be the same for a non-virtual method without default
values.

Arne




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Thread

How to assign an object to another in it method? parmenides <xparmenides@yahoo.com> - 2017-06-18 20:02 +0800
  Re: How to assign an object to another in it method? Eric Sosman <esosman@comcast-dot-net.invalid> - 2017-06-18 08:09 -0400
  Re: How to assign an object to another in it method? Robert Klemme <shortcutter@googlemail.com> - 2017-06-18 15:31 +0200
  Re: How to assign an object to another in it method? Eric Sosman <esosman@comcast-dot-net.invalid> - 2017-06-19 10:22 -0400
    Re: How to assign an object to another in it method? Eric Douglas <e.d.programmer@gmail.com> - 2017-06-19 08:13 -0700
      Re: How to assign an object to another in it method? Eric Sosman <esosman@comcast-dot-net.invalid> - 2017-06-19 11:53 -0400
        Re: How to assign an object to another in it method? Eric Douglas <e.d.programmer@gmail.com> - 2017-06-19 09:06 -0700
          Re: How to assign an object to another in it method? Eric Sosman <esosman@comcast-dot-net.invalid> - 2017-06-19 13:56 -0400
      Re: How to assign an object to another in it method? lewbloch@gmail.com - 2017-06-27 13:49 -0700
        Re: How to assign an object to another in it method? Andreas Leitgeb <avl@logic.at> - 2017-06-28 12:20 +0000
          Re: How to assign an object to another in it method? Eric Douglas <e.d.programmer@gmail.com> - 2017-06-28 05:51 -0700
            Re: How to assign an object to another in it method? Eric Sosman <esosman@comcast-dot-net.invalid> - 2017-06-28 14:03 -0400
            Re: How to assign an object to another in it method? Arne Vajhøj <arne@vajhoej.dk> - 2017-07-02 21:23 -0400
              Re: How to assign an object to another in it method? Martin Gregorie <martin@address-in-sig.invalid> - 2017-07-03 10:59 +0000
                Re: How to assign an object to another in it method? Arne Vajhøj <arne@vajhoej.dk> - 2017-07-03 08:38 -0400
                Re: How to assign an object to another in it method? Andreas Leitgeb <avl@logic.at> - 2017-07-03 14:04 +0000
                Re: How to assign an object to another in it method? Jerry Stuckle <jstucklex@attglobal.net> - 2017-07-03 10:39 -0400
                Re: How to assign an object to another in it method? Andreas Leitgeb <avl@logic.at> - 2017-07-03 16:28 +0000
                Re: How to assign an object to another in it method? Jerry Stuckle <jstucklex@attglobal.net> - 2017-07-03 16:52 -0400
                Re: How to assign an object to another in it method? Arne Vajhøj <arne@vajhoej.dk> - 2017-07-03 22:04 -0400
                Re: How to assign an object to another in it method? Jerry Stuckle <jstucklex@attglobal.net> - 2017-07-03 23:15 -0400
                Re: How to assign an object to another in it method? Arne Vajhøj <arne@vajhoej.dk> - 2017-07-04 21:46 -0400
                Re: How to assign an object to another in it method? Jerry Stuckle <jstucklex@attglobal.net> - 2017-07-04 22:18 -0400
                Re: How to assign an object to another in it method? Arne Vajhøj <arne@vajhoej.dk> - 2017-07-08 21:13 -0400
                Re: How to assign an object to another in it method? Jerry Stuckle <jstucklex@attglobal.net> - 2017-07-08 22:12 -0400
                Re: How to assign an object to another in it method? Andreas Leitgeb <avl@logic.at> - 2017-07-11 17:56 +0000
                Re: How to assign an object to another in it method? Jerry Stuckle <jstucklex@attglobal.net> - 2017-07-11 15:40 -0400
                Re: How to assign an object to another in it method? Eric Douglas <e.d.programmer@gmail.com> - 2017-07-11 13:49 -0700
                Re: How to assign an object to another in it method? Jerry Stuckle <jstucklex@attglobal.net> - 2017-07-11 17:41 -0400
                Re: How to assign an object to another in it method? Arne Vajhøj <arne@vajhoej.dk> - 2017-07-11 20:27 -0400
                Re: How to assign an object to another in it method? Jerry Stuckle <jstucklex@attglobal.net> - 2017-07-11 21:43 -0400
                Re: How to assign an object to another in it method? Arne Vajhøj <arne@vajhoej.dk> - 2017-07-11 21:49 -0400
                Re: How to assign an object to another in it method? Jerry Stuckle <jstucklex@attglobal.net> - 2017-07-12 17:20 -0400
                Re: How to assign an object to another in it method? Andreas Leitgeb <avl@logic.at> - 2017-07-13 10:08 +0000
                Re: How to assign an object to another in it method? Martin Gregorie <martin@address-in-sig.invalid> - 2017-07-13 11:35 +0000
                Re: How to assign an object to another in it method? Arne Vajhøj <arne@vajhoej.dk> - 2017-07-13 08:14 -0400
                Re: How to assign an object to another in it method? Martin Gregorie <martin@address-in-sig.invalid> - 2017-07-13 14:29 +0000
                Re: How to assign an object to another in it method? Arne Vajhøj <arne@vajhoej.dk> - 2017-07-13 13:47 -0400
                Re: How to assign an object to another in it method? Andreas Leitgeb <avl@logic.at> - 2017-07-13 18:09 +0000
                Re: How to assign an object to another in it method? Arne Vajhøj <arne@vajhoej.dk> - 2017-07-13 15:01 -0400
                Re: How to assign an object to another in it method? Andreas Leitgeb <avl@logic.at> - 2017-07-13 19:19 +0000
                Re: How to assign an object to another in it method? Arne Vajhøj <arne@vajhoej.dk> - 2017-07-13 15:39 -0400
                Re: How to assign an object to another in it method? Andreas Leitgeb <avl@logic.at> - 2017-07-13 16:49 +0000
                Re: How to assign an object to another in it method? Jerry Stuckle <jstucklex@attglobal.net> - 2017-07-13 10:24 -0400
                Re: How to assign an object to another in it method? Andreas Leitgeb <avl@logic.at> - 2017-07-13 17:19 +0000
                Re: How to assign an object to another in it method? Arne Vajhøj <arne@vajhoej.dk> - 2017-07-13 21:17 -0400
                Re: How to assign an object to another in it method? Andreas Leitgeb <avl@logic.at> - 2017-07-14 06:40 +0000
                Re: How to assign an object to another in it method? Arne Vajhøj <arne@vajhoej.dk> - 2017-07-14 14:26 -0400
                Re: How to assign an object to another in it method? Andreas Leitgeb <avl@logic.at> - 2017-07-15 14:36 +0000
                Re: How to assign an object to another in it method? Jerry Stuckle <jstucklex@attglobal.net> - 2017-07-14 12:10 -0400
                Re: How to assign an object to another in it method? Arne Vajhøj <arne@vajhoej.dk> - 2017-07-14 14:40 -0400
                Re: How to assign an object to another in it method? Jerry Stuckle <jstucklex@attglobal.net> - 2017-07-14 14:51 -0400
                Re: How to assign an object to another in it method? Arne Vajhøj <arne@vajhoej.dk> - 2017-07-14 21:05 -0400
                Re: How to assign an object to another in it method? Arne Vajhøj <arne@vajhoej.dk> - 2017-07-14 21:06 -0400
                Re: How to assign an object to another in it method? lewbloch@gmail.com - 2017-07-14 14:44 -0700
                Re: How to assign an object to another in it method? Andreas Leitgeb <avl@logic.at> - 2017-07-12 16:23 +0000
                Re: How to assign an object to another in it method? Eric Douglas <e.d.programmer@gmail.com> - 2017-07-12 10:12 -0700
                Re: How to assign an object to another in it method? Arne Vajhøj <arne@vajhoej.dk> - 2017-07-11 20:16 -0400
                Re: How to assign an object to another in it method? Jerry Stuckle <jstucklex@attglobal.net> - 2017-07-11 21:46 -0400
                Re: How to assign an object to another in it method? Arne Vajhøj <arne@vajhoej.dk> - 2017-07-11 21:52 -0400
                Re: How to assign an object to another in it method? Arne Vajhøj <arne@vajhoej.dk> - 2017-07-11 20:24 -0400
                Re: How to assign an object to another in it method? Jerry Stuckle <jstucklex@attglobal.net> - 2017-07-11 21:49 -0400
                Re: How to assign an object to another in it method? Arne Vajhøj <arne@vajhoej.dk> - 2017-07-11 21:55 -0400
                Re: How to assign an object to another in it method? Martin Gregorie <martin@address-in-sig.invalid> - 2017-07-03 12:37 +0000
                Re: How to assign an object to another in it method? Eric Sosman <esosman@comcast-dot-net.invalid> - 2017-07-03 11:34 -0400
                Re: How to assign an object to another in it method? Martin Gregorie <martin@address-in-sig.invalid> - 2017-07-03 17:28 +0000
  Re: How to assign an object to another in it method? v_borchert@despammed.com (Volker Borchert) - 2017-06-19 17:13 +0000
  Re: How to assign an object to another in it method? Eric Douglas <e.d.programmer@gmail.com> - 2017-06-19 13:40 -0700

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