Groups > comp.lang.java.programmer > #34370

Re: how does one explain this syntax?

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From	Robert Klemme <shortcutter@googlemail.com>
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Subject	Re: how does one explain this syntax?
Date	Sun, 22 May 2016 22:22:47 +0200
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On 22.05.2016 17:41, Knute Johnson wrote:

> It's not a modern example of how to iterate over a TreeMap but I suspect
> that it was also to give an example of how to use Map.Entry.  If you
> just want to print out the entries of the map in order you would use
> something similar to this now.
>
> import java.util.*;
>
> public class test {
>      public static void main(String... args) {
>          TreeMap<Integer,String> tmap = new TreeMap<>();
>          tmap.put(1,"Data1");
>          tmap.put(23,"Data2");
>          tmap.put(70,"Data3");
>          tmap.put(4,"Data4");
>          tmap.put(2,"Data5");
>
>          for (Integer key : tmap.keySet())
>              System.out.printf("key is: %d & value is: %s\n",
>               key,tmap.get(key));
>      }
> }

And why not do this instead?

     for (final Entry<Integer, String> entry : tmap.entrySet())
       System.out.printf("key is: %d & value is: %s\n", entry.getKey(), 
entry.getValue());

Note: tmap.get(key) is usually less efficient than fetching the value 
from an Entry.

Kind regards

	robert

-- 
remember.guy do |as, often| as.you_can - without end
http://blog.rubybestpractices.com/

Thread

how does one explain this syntax? ruben safir <ruben@mrbrklyn.com> - 2016-05-22 01:51 -0400
  Re: how does one explain this syntax? Martin Gregorie <martin@address-in-sig.invalid> - 2016-05-22 10:05 +0000
  Re: how does one explain this syntax? Eric Sosman <esosman@comcast-dot-net.invalid> - 2016-05-22 07:21 -0400
    Re: how does one explain this syntax? Popping mad <rainbow@colition.gov> - 2016-05-22 20:21 +0000
      Re: how does one explain this syntax? Lars Enderin <lars.enderin@telia.com> - 2016-05-22 22:32 +0200
      Re: how does one explain this syntax? Eric Sosman <esosman@comcast-dot-net.invalid> - 2016-05-22 17:32 -0400
      Re: how does one explain this syntax? Lew <lewbloch@gmail.com> - 2016-05-23 14:36 -0700
    Re: how does one explain this syntax? Lew <lewbloch@gmail.com> - 2016-05-23 14:34 -0700
  Re: how does one explain this syntax? Knute Johnson <nospam@rabbitbrush.frazmtn.com> - 2016-05-22 08:41 -0700
    Re: how does one explain this syntax? Robert Klemme <shortcutter@googlemail.com> - 2016-05-22 22:22 +0200
      Re: how does one explain this syntax? Knute Johnson <nospam@rabbitbrush.frazmtn.com> - 2016-05-22 22:13 -0700
        Re: how does one explain this syntax? Eric Sosman <esosman@comcast-dot-net.invalid> - 2016-05-23 07:32 -0400
          Re: how does one explain this syntax? Robert Klemme <shortcutter@googlemail.com> - 2016-05-23 04:57 -0700
  Re: how does one explain this syntax? Popping mad <rainbow@colition.gov> - 2016-05-22 20:23 +0000
  Re: how does one explain this syntax? Roedy Green <inquiry@mindprod.com> - 2016-05-30 21:51 -0700
  Re: how does one explain this syntax? Roedy Green <inquiry@mindprod.com> - 2016-05-30 21:54 -0700
  Re: how does one explain this syntax? Roedy Green <inquiry@mindprod.com> - 2016-05-30 22:00 -0700
  Re: how does one explain this syntax? Roedy Green <inquiry@mindprod.com> - 2016-05-30 22:17 -0700

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