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Java Collection, LinkedList Exercises: Get the first and last occurrence of the specified elements in a linked list

Java Collection, LinkedList Exercises: Exercise-10 with Solution

Write a Java program to get the first and last occurrence of the specified elements in a linked list.

Sample Solution:-

Java Code:

import java.util.LinkedList;
import java.util.Iterator;
  public class Exercise10 {
  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);  
 
   // Find first element of the List
    Object first_element = l_list.getFirst();
    System.out.println("First Element is: "+first_element);
 
    // Find last element of the List
    Object last_element = l_list.getLast();
    System.out.println("Last Element is: "+last_element);
 }
}

Sample Output:

Original linked list:[Red, Green, Black, Pink, orange]                 
First Element is: Red                                                  
Last Element is: orange

Pictorial Presentation:

Java Collection Linked-list: Get the first and last occurrence of the specified elements in a linked list.

Flowchart:

Flowchart: Get the first and last occurrence of the specified elements in a 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