Your solution very useful for two Dimensional array with same length.
My question is, can we sort two dimensional array based on some row and based on data length. for example we have an array {{”c”}, {”c”}, {”c”, “d”},{”c”, “a”},{”b”}}. how to get the sorted array like this {{”b”},{”c”},{”c”},{”c”,”a”},{”c”, “d”}}.

Thx a lot Nitin.

public class Sorter {

@SuppressWarnings(“unchecked”)
public static void sort(final T[][] toSort,
final int onColumn) {
List list = Arrays.asList(toSort);
Collections.sort(list, new Comparator() {
public int compare(T[] a, T[] b) {
return a[onColumn].compareTo(b[onColumn]);
}

@Override
public int compare(Object o1, Object o2) {
T[] a = (T[])o1;
T[] b = (T[])o2;
return compare(a,b);
}
});
}

public static void main(String[] args) {
final String[][] array = new String[][] { { “foo”, “bar” },
{ “a”, “b” }, { “me”, “you” }, { “by”, “now” } };

System.out.println(Arrays.deepToString(array));
Sorter.sort(array, 0);
System.out.println(Arrays.deepToString(array));
}
}

I just formatted your comment to make it clear for the readers, I hope you don’t mind.

Regards,

package example.sort2d;

import java.util.Arrays;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;

public class Sorter {

public static <T extends Comparable<T>> void sort(final T [][] toSort,final int onColumn) {
List<T[]> list = Arrays.asList(toSort);
Collections.sort(list, new Comparator<T[]>(){
public int compare(T[] a, T[] b) {
return a[onColumn].compareTo(b[onColumn]);
}
});
}
}

This blog might use some preview, that would be helpful.

I will keep that in mind, its just that I transition between different languages daily that sometimes they get mixed up.

Regards,

Its no problem, and I think you are missing < T[] > from your comparator declaration, which is causing the compilation error, probably what geek is talking about.

It should be:

new Comparator< T[] >() { …

Regards,

@Lars : Thanks for the alternative. It was helpful too!

@geek : It’s you who should “do some groundwork before posting!”

Hi Nitin,

First of all sorry, my comment may have sounded more harsh than it was supposed to be. And you are right, somehow i stopped reading before your “note” (I must admit it was late here).

@geek
Sorry, i don’t understand your point. Please have a look at http://java.sun.com/javase/6/docs/api/java/util/Comparator.html#compare(T, T)

Best regards,
Lars