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Java Collection, LinkedList Exercises: Insert elements into the linked list at the first and last position

Java Collection, LinkedList Exercises: Exercise-6 with Solution

Write a Java program to insert elements into the linked list at the first and last position.

Sample Solution:-

Java Code:

import java.util.LinkedList;
  public class Exercise6 {
  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");
     System.out.println("Original linked list:" + l_list);    
   // Add an element at the beginning 
    l_list.addFirst("White");
 
   // Add an element at the end of list 
    l_list.addLast("Pink");
     System.out.println("Final linked list:" + l_list);  
 }
}

Sample Output:

Original linked list:[Red, Green, Black]                               
Final linked list:[White, Red, Green, Black, Pink]

Pictorial Presentation:

Java Collection Linked-list: Insert elements into the linked list at the first and last position.

Flowchart:

Flowchart: Insert the specified element at the specified position in the linked list.

Java Code Editor:

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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