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Groups > comp.lang.java.programmer > #36839

Re: null checks

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On 7/8/2017 5:14 PM, Martin Gregorie wrote:
> On Sat, 08 Jul 2017 22:33:36 +0200, Joerg Meier wrote:
>> On Fri, 7 Jul 2017 12:12:04 -0400, Arne Vajhøj wrote:
>>> I don't like to rely on IDE/checktool to enforce integrity of
>>> application.
>>
>> Why not ? You presumably let a tool do your type checking for you all
>> the time. Where is the difference to null checking ?
>>
> I'm with Arne here.
> 
> Type checking can generally be done at compile time because its static
> w.r.t code statements.
> 
> However, the same doesn't apply to null checks. Whether a reference
> variable contains null or not depends on what has been assigned to it
> while the code was executing. Whether a null value is valid is entirely
> dependent on the logic of the code using it and so often cannot be
> checked at compile time.

It is very difficult to check for:
    method requiring non null parameter called with null

But I think the typical check is:
    method requiring non null parameter called with something that is 
not guaranteed to be non null

I don't think I would mind it if it got build into the language and
was checked by the compiler. That would just be additional type safety.

But I am not keen on relying on some tool having been run with no
way to verify if it has.

Arne

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null checks Eric Douglas <e.d.programmer@gmail.com> - 2017-07-07 08:03 -0700
  Re: null checks Arne Vajhøj <arne@vajhoej.dk> - 2017-07-07 11:49 -0400
    Re: null checks Eric Douglas <e.d.programmer@gmail.com> - 2017-07-07 08:54 -0700
      Re: null checks Arne Vajhøj <arne@vajhoej.dk> - 2017-07-07 12:12 -0400
        Re: null checks Eric Douglas <e.d.programmer@gmail.com> - 2017-07-07 10:16 -0700
        Re: null checks Joerg Meier <joergmmeier@arcor.de> - 2017-07-08 22:33 +0200
          Re: null checks Martin Gregorie <martin@address-in-sig.invalid> - 2017-07-08 21:14 +0000
            Re: null checks Eric Sosman <esosman@comcast-dot-net.invalid> - 2017-07-08 17:51 -0400
              Re: null checks Martin Gregorie <martin@address-in-sig.invalid> - 2017-07-08 22:26 +0000
            Re: null checks Arne Vajhøj <arne@vajhoej.dk> - 2017-07-08 18:28 -0400
            Re: null checks Joerg Meier <joergmmeier@arcor.de> - 2017-07-25 07:26 +0200
              Re: null checks Martin Gregorie <martin@address-in-sig.invalid> - 2017-07-25 12:12 +0000
          Re: null checks Arne Vajhøj <arne@vajhoej.dk> - 2017-07-08 18:20 -0400
            Re: null checks Eric Douglas <e.d.programmer@gmail.com> - 2017-07-10 05:35 -0700
        Re: null checks Robert Klemme <shortcutter@googlemail.com> - 2017-07-09 13:10 +0200
      Re: null checks Eric Sosman <esosman@comcast-dot-net.invalid> - 2017-07-07 12:53 -0400
        Re: null checks lewbloch@gmail.com - 2017-07-26 11:16 -0700
          Re: null checks Eric Douglas <e.d.programmer@gmail.com> - 2017-07-26 11:40 -0700
            Re: null checks Eric Sosman <esosman@comcast-dot-net.invalid> - 2017-07-26 16:40 -0400
            Re: null checks lewbloch@gmail.com - 2017-07-28 18:47 -0700
  Re: null checks Wayne <wayne@nospam.invalid> - 2017-07-07 16:24 -0400
  Re: null checks Joerg Meier <joergmmeier@arcor.de> - 2017-07-08 22:32 +0200
  Re: null checks Lothar Kimmeringer <news201705@kimmeringer.de> - 2017-07-09 15:59 +0200
    Re: null checks Arne Vajhøj <arne@vajhoej.dk> - 2017-07-11 20:30 -0400

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