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]