Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]


Groups > comp.lang.java.programmer > #24926

Re: Cost of creating objects?

From Jukka Lahtinen <jtfjdehf@hotmail.com.invalid>
Newsgroups comp.lang.java.programmer
Subject Re: Cost of creating objects?
Organization N/A
References (1 earlier) <code-review-20130807173646@ram.dialup.fu-berlin.de> <ktu1eu$dbt$1@news.albasani.net> <ktu8h4$ftf$1@dont-email.me> <d0ae8f7d-89a1-44f8-ac8c-8c7e9038dc1e@googlegroups.com> <ktuq3e$amp$1@dont-email.me>
Message-ID <lvd2pobne0.fsf@saunalahti.fi> (permalink)
Date 2013-08-08 11:24 +0300

Show all headers | View raw


Eric Sosman <esosman@comcast-dot-net.invalid> writes:
> On 8/7/2013 7:52 PM, Lew wrote:

>> Overrule him. He's an idiot. Although doing a 'containsKey()' before a
>> get()' is silly.

>     Situation: A Map that is searched for keys that are usually
> *not* present (poor man's Bloom filter, say), and some of whose
> mapped values are null.  Now, attend:

> 	if (map.containsKey(key)) {  // usually false
> 	    Value val = map.get(key);  // seldom needed
> 	    ...
> 	}
> vs.
> 	Value val = map.get(key);
> 	if (val == null   // usually true
> 	    || map.containsKey(key)  // usually false
> 	) {

I think you mean

   Value val = map.get(key);
   if (val != null // usually false
   ||  map.containsKey(key)) {  // usually false

-- 
Jukka Lahtinen

Back to comp.lang.java.programmer | Previous | NextPrevious in thread | Next in thread | Find similar | Unroll thread


Thread

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

csiph-web