The getFirst() method of the class java.util.LinkedList returns the first element of the current list. Example Live Demo import java.util.*; public class LinkedListDemo { public static void main(String[] args) { LinkedList list = new LinkedList(); list.add("Hello"); list.add(2); list.add("Chocolate"); list.add("10"); System.out.println("LinkedList:" + list); System.out.println("First Element :" + list.getFirst()); } } Output LinkedList:[Hello, 2, Chocolate, 10] First Element :Hello

The addLast(E e) method of the java.util.LinkedList class inserts the specified element at the end of this list.Example:import java.util.*; public class LinkedListDemo {    public static void main(String[] args) {       LinkedList list = new LinkedList();       list.add("Hello");       list.add(2);       list.add("Chocolate");       list.add("10");       System.out.println("LinkedList:" + list);       list.addLast("Element");       System.out.println("LinkedList:" + list);    } }Output:LinkedList:[Hello, 2, Chocolate, 10] LinkedList:[Hello, 2, Chocolate, 10, Element]

The addFirst(E e) method of the class java.util.LinkedList inserts the specified element at the beginning of this list.Example:public class LinkedListDemo {    public static void main(String[] args) {       LinkedList list = new LinkedList();       list.add("Hello");       list.add(2);       list.add("Chocolate");       list.add("10");       System.out.println("LinkedList:" + list);       list.addFirst("Element");       System.out.println("LinkedList:" + list);    } }Output:LinkedList:[Hello, 2, Chocolate, 10] LinkedList:[Element, Hello, 2, Chocolate, 10]

The add(int index, E element) method of the java.util.ArrayList class inserts the specified element E at the specified position in this list. It shifts the element currently at that position (if any) and any subsequent elements to the right (will add one to their indices).Exampleimport java.util.ArrayList; public class ArrayListDemo {    public static void main(String[] args) {       ArrayList arrlist = new ArrayList(5);       arrlist.add(15);       arrlist.add(22);       arrlist.add(30);       arrlist.add(40);       arrlist.add(2,25);       for (Integer number : arrlist) {          System.out.println("Number = " + number);       }    } }OutputNumber = 15 Number = 22 Number = 25 Number = 30 Number = 40

The add(E e) method of the java.util.ArrayList class appends the specified element E to the end of the list.Example:import java.util.ArrayList; public class ArrayListDemo {    public static void main(String[] args) {       ArrayList arrlist = new ArrayList(5);       arrlist.add(15);       arrlist.add(20);       arrlist.add(25);       for (Integer number : arrlist) {          System.out.println("Number = " + number);       }    } }Output:Number = 15 Number = 20 Number = 25

The removeRange() method of the ArrayList class removes all of the elements from this List whose index is between fromIndex and toIndex.Exampleimport java.util.*; public class ArrayListDemo extends ArrayList{    public static void main(String[] args) {       ArrayListDemo arrlist = new ArrayListDemo();       arrlist.add(10);       arrlist.add(12);       arrlist.add(31);       System.out.println("The list:" + arrlist);       arrlist.removeRange(0,2);       System.out.println("The list after using removeRange:" + arrlist);    } }OutputThe list:[10, 12, 31] The list after using removeRange:[31]

The set() method of the ArrayList class replaces the element at the specified position in this list with the specified element.Exampleimport java.util.ArrayList; public class Sample {    public static void main(String args[]) {       ArrayList al = new ArrayList();       System.out.println("Initial size of al: " + al.size());       al.add("C");       al.add("A");       al.add("E");       al.add(1, "A2");       System.out.println("Size of al after additions: " + al.size());       System.out.println("Contents of al: " + al);       System.out.println("Size of al after deletions: " + al.size());     ... Read More

The listIterator(int index) method of the java.util.LinkedList class returns a list-iterator of the elements in this list (in proper sequence), starting at the specified position in the list. Example import java.util.*; public class LinkedListDemo { public static void main(String[] args) { LinkedList list = new LinkedList(); list.add("Hello"); list.add(2); list.add("Chocolate"); list.add("10"); System.out.println("LinkedList:" + list); Iterator x = list.listIterator(1); while (x.hasNext()) { System.out.println(x.next()); } } } Output LinkedList:[Hello, 2, Chocolate, 10] 2 Chocolate 10

The trimToSize() method of the java.util.ArrayList class trims the capacity of this ArrayList instance to be the list's current size. An application can use this operation to minimize the storage of an ArrayList instance.Exampleimport java.util.ArrayList; public class ArrayListDemo {    public static void main(String args[]) {       ArrayList arrlist = new ArrayList(5);       arrlist.add(35);       arrlist.add(20);       arrlist.add(25);       arrlist.trimToSize();       for (Integer number : arrlist) {          System.out.println("Number = " + number);       }    } }OutputNumber = 35 Number = 20 Number = 25

Since a vector stores elements in the form of objects, you can store objects of various types (heterogeneous) in it.Example:import java.util.*; class Demo{} public class VectorSample {    public static void main(String args[]) {       Demo obj = new Demo();       Vector v = new Vector(3, 2);       System.out.println("Initial size: " + v.size());       System.out.println("Initial capacity: " + v.capacity());       v.addElement(new Integer(1));       v.addElement(new String("krishna"));       v.addElement(new Float(3.5f));       v.addElement(obj);       System.out.println("Capacity after four additions: " + v.capacity());    } }