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Please explain the code.

 
Ranch Hand
Posts: 148
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Hi All,

Can anybody explain me the the code.



Thanks
 
Rancher
Posts: 1776
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The class implements the Comparator interface. So when a Array.sort() method is called, it uses the specified comparator (here the class VLA2) to compare objects during sorting.

The VLA2 class overrides the compare() method of the Comparator interface. This is the method that will be called to compare objects.

Please read the specifications - Comparator:compare(), http://download.oracle.com/javase/6/docs/api/java/util/Arrays.html#sort(T[], java.util.Comparator) and the Comparators section in Object Ordering Tutorials.

I think the compare method written in the code is wrong. According to the specification it should return a negative int / zero or a positive int. But it just assigns the given a's dish value to b and returns it.

And http://download.oracle.com/javase/6/docs/api/java/util/Arrays.html#binarySearch(T[], T, java.util.Comparator) is used
to search the given object, using the given comparator in the given array.

I have modified the compare() method and added some System.out.println() and two more objects in the array in the code shown below.
Note that binarySearch() method uses the comparator to find the object.


 
Ranch Hand
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yes, the compare method is very badly implemented. The following code includes binarySearch(as it is done in Arrays class) gives you more clarity. Includes overriden toString() method




 
It is sorta covered in the JavaRanch Style Guide.
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