w3resource

Java Collection, LinkedList Exercises: Iterate a linked list in reverse order.

Java Collection, LinkedList Exercises: Exercise-4 with Solution

Write a Java program to iterate a linked list in reverse order.

Sample Solution:-

Java Code:

import java.util.LinkedList;
import java.util.Iterator;
  public class Exercise4 {
  public static void main(String[] args) {
    // create an empty linked list
     LinkedList<String> l_list = new LinkedList<String>();
   // use add() method to add values in the linked list
          l_list.add("Red");
          l_list.add("Green");
          l_list.add("Black");
          l_list.add("Pink");
          l_list.add("orange");
      
        // print original list
   System.out.println("Original linked list:" + l_list);  
 
    Iterator it = l_list.descendingIterator();

     // Print list elements in reverse order
     System.out.println("Elements in Reverse Order:");
     while (it.hasNext()) {
        System.out.println(it.next());
     }
  }
}

Sample Output:

Original linked list:[Red, Green, Black, Pink, orange]                 
Elements in Reverse Order:                                             
orange                                                                 
Pink                                                                   
Black                                                                  
Green                                                                  
Red

Pictorial Presentation:

Java Collection Linked-list: Iterate a linked list in reverse order.

Flowchart:

Flowchart: Iterate a linked list in reverse order.

Java Code Editor:

Contribute your code and comments through Disqus.

What is the difficulty level of this exercise?



Java: Tips of the Day

Try and catch:

Java is excellent at catching errors, but it can only recover gracefully if you tell it what to do. The cascading hierarchy of attempting to perform an action in Java starts with try, falls back to catch, and ends with finally. Should the try clause fail, then catch is invoked, and in the end, there's always finally to perform some sensible action regardless of the results. Here's an example:

try {
        cmd = parser.parse(opt, args); 
       
        if(cmd.hasOption("help")) {
                HelpFormatter helper = new HelpFormatter();
                helper.printHelp("Hello ", opt);
                System.exit(0);
                }
        else {
                if(cmd.hasOption("shell") || cmd.hasOption("s")) {
                String target = cmd.getOptionValue("tgt");
                } // else
        } // fi
} catch (ParseException err) {
        System.out.println(err);
        System.exit(1);
        } //catch
        finally {
                new Hello().helloWorld(opt);
        } //finally
} //try

It's a robust system that attempts to avoid irrecoverable errors or, at least, to provide you with the option to give useful feedback to the user. Use it often, and your users will thank you!

Ref: https://red.ht/3EZc9OC