1. Class is a blueprint (or) model for creating the objects and it doesn’t exist physically.
  2. A class can contains properties and actions.
  3. Properties are represented by variables and actions are represented by methods. بورصة اسعار الذهب مباشر


  1. Object is an instance of a class.An object is any thing that exists physically.
  2. An object also contains properties and actions. كيفيه التداول بالعملات والذهب

konvertor valuta forex forex bez depozytu class Student{ //properties-instance variables String name; int age; // actions-methods void talk(){ System.out.println("Hello i am "+name); System.out.println("My age is "+age); } }

Creating Objects for a class

تداول تجريبي للاسهم السعودية classname objname=new classname(); شبكة تداول الاسهم السعودية Student s=new Student();

  1. Here حسابات الفوركس التي تم إدارتها s variable stores the references number of the object returned by JVM after creating the object.
  2. We know that class code along with method a code is stored in “method area” of the JVM ,When an object is created ,the memory is allocated on “heap”.
  3. After creation of an object ,JVM produces a unique reference number for the object from the memory address of the object,This reference number is also called “ برامج تحليل الاسهم السعودية hashCode” number.
  4. To know the hashCode no(reference) of an object ,we can use hashCode() method of object class.

الخيارات الثنائية العودة للتداول

  1. hashCode is a unique identification number allocated to the objects by the JVM.This hashCode number is also called reference number Which is created based on the location of the object in the memory.
  2. How can you find the hashCode of an object?
    the hashCode() method of ‘Object’ class in java.lang package is useful to find the hashCode of an object

    بيع اسهم اسواق المزرعه class Demo{ public static void main(String args[]){ //create Student class object:p(in the above) Student s=new Student (); System.out.println(s.hashCode());; } } /* Output: 33219526 Hello i am null My age is 0 */

  1. By using hashCode() we can get hashCode number
  2. By using reference variable(s),we can refer instance variables and methods like s. name,s.age,
  3. Since we didn’t initialize instance variables,Java compiler adds some additional code to Student class
    When JVM executes ,preceding code .it stores null into name and 0 into age

The default values of the instance variable are used by java compiler

Datatype Default value
byte 0
short 0
int 0
long 0
float 0.0
double 0.0
char a space
String null
any class type null
boolean false