• Object Creation
• Object Usage
• Object Disposal

• Identity
  Identity makes the object unique from other objects
• State
  State of the object is nothing but the attributes of the object, and they may change during execution of program
• Behavior
  It is defined by the functions/methods that object provides

• Identity : Object name ‘Benz’
• State: Color, model number, gears, price etc
• Behavior: drive(), getPetrol()

Base Class ‘Car’

Creating Object ‘Benz’ for Class ‘Car’

Points to observe

• Here new instance of class ‘car’ is created inside another Test_class  as ‘Benz’ which is called object
• All the variables(isTankEmpty) and the methods(getPetrol() ) of class ‘car’ are only accessed by the objects created for that class.

Conclusions

• Objects have Identity, State, Behavior
• All the methods/Variables of a class  can be accessed only through the object created for that class.

• A Variable which is declared inside class but not in it method is called Class Variable.
• Also called as member Variables.
• In the previous example, model is class variable
• It can be initialized
• The variable declared inside a class, can be accessed to all the code inside a class.

• Variables declared inside method of a class
• They can be used within the method

Class Parameters/Arguments

• These are arguments passed to Classes
• The scope of Class Parameter is just like Class variable entire the class

Method Parameters/Arguments

• These are arguments passed to Methods which are inside classes
• The scope of Method Parameter is for that method
• They cannot be initialized

A typical class definition consists of:

• Class declaration
• Class body
• Variables / Attributes (static / non-static)
• Methods (static / non-static)
• Constructors
• Finalize method (if cleaning up is necessary)

You can simply declare the array using above example. Here myArray[] object is just declared, no memory allocated nor the values are initialized. you can say like the name myArray is declared as Array.

• Array memory allocation:
  int myArray[] = new int[10];

Using the above example you can allocate the memory to an array. Here we are allocating 10 integer values to myArray[] so that the array myArray[] can store up to 10 integer values.

• Array Initialization:
  int myArray[] = {1,2,3,4,5,6,7,8,9,10};

Using the above example you can initialize the values, here myArray[] contains 10 values where myArray[1]=2;

The following table gives the snapshot of Java  control flow statements