Comments on snippet: 'Sorting map keys by comparing it's values'

hohonuuli said on 6/8/07

Fri, 08 Jun 2007 09:45:32 GMT

The equivalent Groovy code to the Java shown is actually:


// create Map 
def lang = [0:"Java", 1:"Groovy", 2:"Ruby", 3:"Python", 4:"C#", 5:"C++", 6:"Perl"] 
// Sort the keys by value 
def keys = lang.keySet().sort {lang[it]} 
// List the key value 
keys.each { println "${it} ${lang[it]}" }

Also, the Java code for Java 5 and 6 could be more like:


final Map lang = new HashMap() {{ 
    put(0, "Java"); put(1, "Groovy"); put(2, "Ruby"); 
    put(3, "Python"); put(4, "C#"); put(5, "C++"); 
    put(6, "Perl"); }}; 
List keys = new ArrayList(lang.keySet()); 
Collections.sort(keys, new Comparator() { 
    public int compare(Integer left, Integer right) { 
        return lang.get(left).compareTo(lang.get(right)) 
    } 
}); 
for (Integer k : keys) { System.out.println(k + " " lang.get(k); }

Groovy definitly requires WAY less scaffolding than Java. On the other hand Java is WAY WAY faster than groovy. (Nothing in life comes free ;-)

hohonuuli said on 6/8/07

Fri, 08 Jun 2007 09:40:50 GMT

The equivalent Groovy code to the Java shown is actually:

// create Map def lang = [0:"Java", 1:"Groovy", 2:"Ruby", 3:"Python", 4:"C#", 5:"C++", 6:"Perl"] // Sort the keys by value def keys = lang.keySet().sort {lang[it]} // List the key value keys.each { println "${it} ${lang[it]}" }

Also, the Java code for Java 5 and 6 could be more like:

final Map lang = new HashMap() {{ put(0, "Java"); put(1, "Groovy"); put(2, "Ruby"); put(3, "Python"); put(4, "C#"); put(5, "C++"); put(6, "Perl"); }}; List keys = new ArrayList(lang.keySet()); Collections.sort(keys, new Comparator() { public int compare(Integer left, Integer right) { return lang.get(left).compareTo(lang.get(right)) } }); for (Integer k : keys) { System.out.println(k + " " lang.get(k); }

Groovy definitly requires WAY less scaffolding than Java. On the other hand Java is WAY WAY faster than groovy. (Nothing in life comes free ;-)