了解使用比较器对多维数组排序

Question

My String array looks like String[][] cat = new String[13][4];

I want to sort all [13] by the 3rd value in the second column "[][2]".

int  myNum = 0;
Arrays.sort(cat, new Comparator<String[]>() {
         @Override
         public int compare(final String[] entry1, final String[] entry2) {
         final String e1 = entry1[1];
         final String e2 = entry2[1];

         return e1.compareTo(e2);
         }
         });

         for (final String[] s : cat) {
         System.out.println("SORTING: "+s[0] + " " + s[1]+ " " + s[2]+ " " + s[3]);
         try {
                myNum = Integer.parseInt(s[2]);
            } catch (NumberFormatException nfe) {
                System.out.println("Could not parse " + nfe);
            }

            if (myNum > 3 && s[1].equals("1")) {
                moreValues2.add(s[1]);
                moreURLS2.add(s[3]);
            }

         } 

How do I choose what value to sort by. In my code above it is sorting by the first column but I wish to sort by the 3rd. I am not sure what to modify and why to modify it.
I read http://docs.oracle.com/javase/6/docs/api/java/util/Comparator.html to no avail. and version 7

Answer 1

In your comparator, the values are picked here :

final String e1 = entry1[1];
final String e2 = entry2[1];

Simply replace [1] with [2], or [3] (since I don't understand "third value in the second column").

Answer 2

代替final String[] s : cat可以将final String s : cat[2]放到第三行，然后对它们进行排序