Collections methods reverse, fill, copy, max and min. - Java Collection Framework

Java examples for Collection Framework:Collections Utility Methods

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Description

Collections methods reverse, fill, copy, max and min.

Demo Code

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

public class Main 
{
   public static void main(String[] args)
   {//from ww w.  j  a v a 2s.  co  m
      // create and display a List< Character >
      Character[] letters = {'P', 'C', 'M'};
      List<Character> list = Arrays.asList(letters); // get List
      System.out.println("list contains: ");
      output(list);

      // reverse and display the List<Character>
      Collections.reverse(list); // reverse order the elements
      System.out.printf("%nAfter calling reverse, list contains:%n");
      output(list);

      // create copyList from an array of 3 Characters
      Character[] lettersCopy = new Character[3]; 
      List<Character> copyList = Arrays.asList(lettersCopy); 

      // copy the contents of list into copyList
      Collections.copy(copyList, list);
      System.out.printf("%nAfter copying, copyList contains:%n");
      output(copyList);

      // fill list with Rs 
      Collections.fill(list, 'R'); 
      System.out.printf("%nAfter calling fill, list contains:%n");
      output(list);
   } 

   // output List information
   private static void output(List<Character> listRef)
   {
      System.out.print("The list is: ");

      for (Character element : listRef)
         System.out.printf("%s ", element);

      System.out.printf("%nMax: %s", Collections.max(listRef));
      System.out.printf("  Min: %s%n", Collections.min(listRef));
   } 
}

Result


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