The peek() method is used to look at the object at the top of this stack without removing it from the stack.Exampleimport java.util.*; public class StackDemo {    public static void main(String args[]) {             Stack st = new Stack();       st.push("Java");       st.push("Source");       st.push("code");       System.out.println("Top object is: "+st.peek());    } }OutputTop object is: code

Java is a programming language, whereas Core Java is a computing platform. Java Platform Standard Edition is Core Java, which is also called Java SE. The following are the computing following supported by Java, which also has Core Java as its part:Java SE Java Standard Edition used to develop desktop applications. A well-known implementation of Java SE is the Java Development Kit (JDK).Java EE Java Enterprise Edition i.e. Java 2 Platform, Enterprise Edition or J2EE. Java EE is used for applications running on servers. Java ME Java Micro Edition is used for applications running on mobile phones.Java SE is the Standard Edition and also ... Read More

The pop() method is used to remove the object at the top of this stack and returns that object as the value of this function. Example import java.util.*; public class StackDemo { public static void main(String args[]) { Stack st = new Stack(); st.push("Java"); st.push("Source"); st.push("code"); System.out.println("Removed object is: "+st.pop()); System.out.println("Elements after remove: "+st); } } Output Removed object is: code Elements after remove: [Java, Source]

The toArray() method of the java.util.ArrayList class returns an array containing all of the elements in this list in proper sequence (from first to the last element).This acts as a bridge between array-based and collection-based APIs.Exampleimport java.util.ArrayList; public class ArrayListDemo {    public static void main(String[] args) {       ArrayList arrlist = new ArrayList(5);       arrlist.add(20);       arrlist.add(40);       arrlist.add(10);       arrlist.add(15);       arrlist.add(25);       for (Integer number : arrlist) {          System.out.println("Number = " + number);       }       Object[] ... Read More

The push(Object item) method is used to Pushes an item onto the top of this stack.Exampleimport java.util.*; public class StackDemo {    public static void main(String args[]) {       Stack st = new Stack();       st.push("Java");       st.push("Source");       st.push("code");       System.out.println("Elements in the stack: "+st);    } }OutputElements in the stack: [Java, Source, code]

The elements() method is used to return an enumeration of the components of this vector. The returned Enumeration object will generate all items in this vector at the similar index location.Exampleimport java.util.Vector; public class VectorDemo {    public static void main(String[] args) {             Vector vec = new Vector(4);       vec.add(4);       vec.add(3);       vec.add(2);       vec.add(1);       Enumeration e=vec.elements();       System.out.println("Numbers in the enumeration are :- ");       while (e.hasMoreElements()) {          System.out.println("Number = " + e.nextElement());       }    } }OutputNumbers in the enumeration are :- Number = 4 Number = 3 Number = 2 Number = 1

The contains(Object) method of the java.util.ArrayList class returns true if this list contains the specified element.Exampleimport java.util.ArrayList; public class ArrayListDemo {    public static void main(String[] args) {       ArrayList arrlist = new ArrayList

The isEmpty() method of the class java.util.ArrayList returns true if this list contains no elements.Exampleimport java.util.ArrayList; public class ArrayListDemo {    public static void main(String[] args) {       ArrayList arrlist = new ArrayList(5);       arrlist.add(25);       arrlist.add(10);       arrlist.add(20);       arrlist.add(35);       boolean retval = arrlist.isEmpty();       if (retval == true) {          System.out.println("list is empty");       } else {          System.out.println("list is not empty");       }       for (Integer number : arrlist) {          System.out.println("Number = " + number);       }    } }Outputlist is not empty Number = 25 Number = 10 Number = 20 Number = 35

The capacity() method is used to return the current capacity of a vector. Capacity is the length of the array kept in the vector.Exampleimport java.util.Vector; public class VectorDemo {    public static void main(String[] args) {       Vector vec = new Vector();       vec.add(14);       vec.add(13);       vec.add(12);       vec.add(11);       vec.add(4);       vec.add(3);       vec.add(2);       vec.add(1);       System.out.println("Capacity of the vector is :"+vec.capacity());    } }OutputCapacity of the vector is :10

The size() method of the class java.util.ArrayList returns the number of elements in this list i.e. the size of the list.Exampleimport 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);       arrlist.add(22);       for (Integer number : arrlist) {          System.out.println("Number = " + number);       }       int retval = arrlist.size();       System.out.println("Size of list = " + retval);    } }OutputNumber = 15 Number = 20 Number = 25 Number = 22 Size of list = 4