java sort using anonymous class

anonymous, class, java, sorting

Solution

Finally, I modified the sort function in this manner to get sorted data.

 Collections.sort(ls, new Comparator(){
      
      public int compare(Object o1, Object o2) 
      {
          String sa = (String)o1;
          String sb = (String)o2;
                            
          int v = sa.compareTo(sb);                             
          return v;  // it can also return 0, and 1
         
       }
 });

Problem

I have class in which I am sorting a list. ``` import java.util.*; public class First { private static HashMap<String,Second> msgs; public static void main(String[] args) { List<String> ls=new ArrayList<String>(); ls.add("fourth"); ls.add("2"); ls.add("second"); ls.add("first"); ls.add("third"); ls.add("1"); Iterator it=ls.iterator(); // before sorting while(it.hasNext()) { String s=(String)it.next(); System.out.println(s); } Collections.sort(ls, new Comparator(){ public int compare(Object o1, Object o2) { return -1; // it can also return 0, and 1 } }); System.out.println(" "); //after sorting Iterator iti=ls.iterator(); while(iti.hasNext()) { String s=(String)iti.next(); System.out.println(s); } } } ``` After the program is run, I get these values: ``` 1 third first second 2 fourth ``` My question is what is the behavior of Collection.sort() function here. On returning -1 from compare function, we get the reverse order of the list. Then how can we get other sorting orders? What is the role of returning 0, and 1?

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