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Java Collection, LinkedList Exercises: Remove first and last element from a linked list

Java Collection, LinkedList Exercises: Exercise-13 with Solution

Write a Java program to remove first and last element from a linked list.

Sample Solution:-

Java Code:

import java.util.*;

  public class Exercise13 {
  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 the list
   System.out.println("The Original linked list: " + l_list);

  // Remove the first element
    Object firstElement = l_list.removeFirst();
    System.out.println("Element removed: "+ firstElement);
 
  // Remove the last element
    Object lastElement = l_list.removeLast();
    System.out.println("Element removed: "+ lastElement);
    System.out.println("The New linked list: " + l_list);
  }
}

Sample Output:

The Original linked list: [Red, Green, Black, Pink, orange]            
Element removed: Red                                                   
Element removed: orange                                                
The New linked list: [Green, Black, Pink]

Pictorial Presentation:

Java Collection Linked-list: Remove first and last element from a linked list.

Flowchart:

Flowchart: Remove first and last element from a linked list

Java Code Editor:

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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
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} 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