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Groups > comp.lang.java.programmer > #24935

Re: Cost of creating objects?

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On 08/08/13 15:42, Arne Vajhøj wrote:
> On 8/8/2013 10:34 AM, Jukka Lahtinen wrote:
>> lipska the kat <"nospam at neversurrender dot co dot uk"> writes:
>>> On 08/08/13 09:24, Jukka Lahtinen wrote:
>>
>>>>      Value val = map.get(key);
>>>>      if (val != null // usually false
>>
>>> I think (null != val ... ) is better.
>>
>> Why? I see no real difference.
>> If you are thinking about NullPointerException, it is not thrown by
>> this kind of comparison, where you just check equality to null without
>> refering any possible members of val.
>
> The trick sometimes called Yoda condition is from C/C++ where
> you could intend to write:
>    if(val == null)
> and end up writing:
>    if(val = null)
> and not get a compile error but instead a different semantics than
> expected.
>
> Writing:
>    if(null == val)
> avoid that risk as:
>    if(null = val)
> will give a compile error.
>
> But Java is different.

It is, damn that C

lipska


-- 
Lipska the Kat©: Troll hunter, sandbox destroyer
and farscape dreamer of Aeryn Sun
GNU/Linux user #560883 - http://www.linuxcounter.net

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Cost of creating objects? Sebastian <news@seyweiler.dyndns.org> - 2013-08-07 09:44 +0200
  Re: Cost of creating objects? Donkey Hottie <donkey@fredriksson.dy.fi> - 2013-08-07 13:02 +0300
    Re: Cost of creating objects? Sebastian <news@seyweiler.dyndns.org> - 2013-08-07 12:05 +0200
      Re: Cost of creating objects? Donkey Hottie <donkey@fredriksson.dy.fi> - 2013-08-07 14:08 +0300
      Re: Cost of creating objects? Eric Sosman <esosman@comcast-dot-net.invalid> - 2013-08-07 08:08 -0400
      Re: Cost of creating objects? Kevin McMurtrie <mcmurtrie@pixelmemory.us> - 2013-08-07 20:14 -0700
        Re: Cost of creating objects? Arved Sandstrom <asandstrom2@eastlink.ca> - 2013-08-08 17:17 -0300
  Re: Cost of creating objects? Joerg Meier <joergmmeier@arcor.de> - 2013-08-07 12:37 +0200
  Re: Cost of creating objects? Sebastian <news@seyweiler.dyndns.org> - 2013-08-07 19:51 +0200
    Re: Cost of creating objects? Eric Sosman <esosman@comcast-dot-net.invalid> - 2013-08-07 15:51 -0400
      Re: Cost of creating objects? Lew <lewbloch@gmail.com> - 2013-08-07 16:52 -0700
        Re: Cost of creating objects? Eric Sosman <esosman@comcast-dot-net.invalid> - 2013-08-07 20:51 -0400
          Re: Cost of creating objects? Jukka Lahtinen <jtfjdehf@hotmail.com.invalid> - 2013-08-08 11:24 +0300
            Re: Cost of creating objects? lipska the kat <"nospam at neversurrender dot co dot uk"> - 2013-08-08 10:07 +0100
              Re: Cost of creating objects? Jukka Lahtinen <jtfjdehf@hotmail.com.invalid> - 2013-08-08 17:34 +0300
                Re: Cost of creating objects? Arne Vajhøj <arne@vajhoej.dk> - 2013-08-08 10:42 -0400
                Re: Cost of creating objects? lipska the kat <"nospam at neversurrender dot co dot uk"> - 2013-08-08 20:45 +0100
              Re: Cost of creating objects? Arne Vajhøj <arne@vajhoej.dk> - 2013-08-08 10:38 -0400
            Re: Cost of creating objects? Eric Sosman <esosman@comcast-dot-net.invalid> - 2013-08-08 10:13 -0400
    Re: Cost of creating objects? Arne Vajhøj <arne@vajhoej.dk> - 2013-08-07 20:28 -0400
      Re: Cost of creating objects? Arved Sandstrom <asandstrom2@eastlink.ca> - 2013-08-08 17:34 -0300
  Re: Cost of creating objects? lipska the kat <"nospam at neversurrender dot co dot uk"> - 2013-08-07 19:19 +0100
    Re: Cost of creating objects? lipska the kat <"nospam at neversurrender dot co dot uk"> - 2013-08-07 19:24 +0100
    Re: Cost of creating objects? Kevin McMurtrie <mcmurtrie@pixelmemory.us> - 2013-08-07 20:03 -0700
      Re: Cost of creating objects? Arved Sandstrom <asandstrom2@eastlink.ca> - 2013-08-08 17:39 -0300
  Re: Cost of creating objects? Arne Vajhøj <arne@vajhoej.dk> - 2013-08-07 20:24 -0400

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