With this example we are going to demonstrate how to add elements in the start and the end of a LinkedList. The LinkedList API provides methods to do such operations. In short, to add elements in the start and the end of a LinkedList you should:
- Create a new LinkedList.
- Populate the list with elements, with
add(E e)API method of LinkedList. - Insert a specified element at the beginning of the list, using
addFirst(E e)API method. - Append a specified element to the end of the list, using
addLast(E e)API method.
Let’s take a look at the code snippet that follows:
package com.javacodegeeks.snippets.core;
import java.util.LinkedList;
public class AddElementsStartEndLinkedList {
public static void main(String[] args) {
// Create a LinkedList and populate it with elements
LinkedList linkedList = new LinkedList();
linkedList.add("element_1");
linkedList.add("element_2");
linkedList.add("element_3");
linkedList.add("element_4");
linkedList.add("element_5");
System.out.println("LinkedList contains : " + linkedList);
// void addFirst(Object obj) operation inserts an object at the beginning of the list
linkedList.addFirst("element_0");
System.out.println("Inserted element_0 at the beginning of the list, LinkedList contains :" + linkedList);
// void addLast(Object obj) method appends an object at the end of the list
linkedList.addLast("element_6");
System.out.println("Appended element_6 at the end of the list, LinkedList contains :" + linkedList);
}
}
Output:
LinkedList contains : [element_1, element_2, element_3, element_4, element_5]
Inserted element_0 at the beginning of the list, LinkedList contains :[element_0, element_1, element_2, element_3, element_4, element_5]
Appended element_6 at the end of the list, LinkedList contains :[element_0, element_1, element_2, element_3, element_4, element_5, element_6]
This was an example of how to add elements in the start and the end of a LinkedList in Java.
