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("Geeks");
        list.add("for");
        list.add("Geeks");
        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:[Geeks, for, Geeks, 10, 20]
The new List is:[Geeks, for, Geeks, 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("Geeks");
        ll.add("For");
        ll.add("Geeks");

        // 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:

[Geeks, For, Geeks]
[Geeks, For, Java, Geeks]