Java Program to Add elements to a LinkedList

Example 1: Add Elements Using add()

 import java.util.LinkedList; class Main { public static void main(String[] args){ // create a linkedlist LinkedList<String> languages = new LinkedList<>(); // Add elements to LinkedList languages.add("Java"); languages.add("Python"); languages.add("JavaScript"); System.out.println("LinkedList: " + languages); } }

Output

 LinkedList: [Java, Python, JavaScript]

Here, the add() method inserts an element at the end of a linkedlist. However, we can also insert elements at the specified position using the add() method.

Example 2: Add element at the specified position

 import java.util.LinkedList; class Main { public static void main(String[] args){ // create a linkedlist LinkedList<String> languages = new LinkedList<>(); // add elements to LinkedList languages.add("Swift"); languages.add("Python"); System.out.println("LinkedList: " + languages); // add element at the specified position languages.add(0, "Java"); System.out.println("Updated LinkedList: " + languages); } }

Output

 LinkedList: [Swift, Python] Updated LinkedList: [Java, Swift, Python]

In the example, notice the line,

 languages.add(0, "Java");

Here, 0 is an optional parameter that specifies the index number where the new element is to be added.

Example 3: All all elements from other collection to LinkedList

To add all the elements of a collection to another linked list, we use the addAll() method.

 import java.util.LinkedList; class Main { public static void main(String[] args) { LinkedList<String> mammals = new LinkedList<>(); mammals.add("Dog"); mammals.add("Cat"); mammals.add("Horse"); System.out.println("Mammals: " + mammals); LinkedList<String> animals = new LinkedList<>(); animals.add("Crocodile"); // Add all elements of mammals in animals animals.addAll(mammals); System.out.println("Animals: " + animals); } }

Output

 Mammals: [Dog, Cat, Horse] Animals: [Crocodile, Dog, Cat, Horse]

Example 4: Using listIterator() method

We can also use the listsIterator() method to add elements to the linked list. To use it, we must import java.util.ListIterator package.

 import java.util.ArrayList; import java.util.ListIterator; class Main { public static void main(String[] args) { ArrayList<String> languages = new ArrayList<>(); // Creating an object of ListIterator ListIterator<String> listIterate = languages.listIterator(); listIterate.add("Java"); listIterate.add("Python"); System.out.println("LinkedList: " + languages); } }

Output

 LinkedList: [Java, Python]