LinkedList add() Method in Java With Examples
LinkedList is a class implementation of the LinkedList data structure which is a linear data structure where the elements are not stored in contiguous locations and every element is a separate object with a data part and address part. As we all know that class contains various methods so do here we will be discussing and implementing add() method to grasp a better understanding of how elements are added in a LinkedList.
For that refer to the below flowchart to get a better understanding of any methods. Note that it is very important to go through flowcharts in programming . Here two cases arises that is default addition of elements and custom addition of elements. Here we will be covering both of them as follows:
Case 1: Default addition by adding at last of List
This method appends the specified element to the end of this list. This function accepts a single parameter element as shown in the above syntax
Syntax:
boolean add(Object element)
Parameters: The element specified by this parameter is appended to the end of the list.
Return Value: Boolean true after execution.
Example:
Java
// Java Program to Illustrate add() Method // of LinkedList class // Where we are Adding at Last of List // Importing required classes import java.io.*; import java.util.LinkedList; // Main class public class GFG { // Main driver method public static void main(String args[]) { // Creating an empty LinkedList LinkedList list = new LinkedList(); // Adding elements in the list // using add() method list.add( "Beginner" ); list.add( "for" ); list.add( "Beginner" ); list.add( "10" ); list.add( "20" ); // Printing the elements of current LinkedList System.out.println( "The list is:" + list); // Adding new elements to the end // Note: Default addition happens from last list.add( "Last" ); list.add( "Element" ); // Printing elements of updated LinkedList System.out.println( "The new List is:" + list); } } |
Output:
The list is:[Beginner, for, Beginner, 10, 20] The new List is:[Beginner, for, Beginner, 10, 20, Last, Element]
Case 2: Adding at the specified index
This method inserts an element at a specified index in the list. It shifts the element currently at that position (if any) and any subsequent elements to the right (will add one to their indices).
Syntax:
void add(int index, Object element)
Parameters: This method accepts two parameters as described below.
- index: The index at which the specified element is to be inserted.
- element: The element which is needed to be inserted.
Return Value: Boolean true after execution.
Example:
Java
// Java Program to Illustrate add() Method // of LinkedList class // Adding at a Specified Index // Importing required classes import java.util.LinkedList; import java.io.*; // Main class class GFG { // Main driver method public static void main(String[] args) { // Creating an empty LinkedList of string type LinkedList<String> ll = new LinkedList(); // Adding elements to LinkedList // using add() method ll.add( "Beginner" ); ll.add( "For" ); ll.add( "Beginner" ); // Printing the current elements of LinkedList System.out.println(ll); // Adding element at a particular index // by passing as an argument ll.add( 2 , "Java" ); // Printing the updated elements of LinkedList // after insertion at specified index System.out.println(ll); } } |
Output:
[Beginner, For, Beginner] [Beginner, For, Java, Beginner]