Variables

Defination:-
->Variables are used to store data.
or
->Variables are named memory location which can store some value/data and it changes 'n' number of times during excution.

⭐We can perform below operations on variables

1.Variable Declaration:-	2.Variable Initialization:-
Syntax:- datatype variable_name; exa:- int a;	Syntax:- variable_name = value; exa:- a=10;
3.Variable Utilization:-	4.Variable Declaration and Initialization:-
exa:- System.out.println(a);	Syntax:- datatype variable_name = value; exa:- int a = 10;

Types of Variables/DataTypes:-

1)Primitive DataTypes.	2)Non-Primitive DataTypes.
1)byte. 2)short. 3)int. 4)long. 5)float. 6)double. 7)char. 8)boolean.	1)Array. 2)String. or Any Class Type.

⭐The Difference Between Primitive and Non-Primitive Datatypes is Size.

⭐Variables are classified into

1)Local Variables	2)Global Variables
Defination:-Any variable which is declared within the method is called as local variable. The scope of local variable is from the begining of method still end of the method. It will not have default value. It cannot be classified into Static or Non-Static. Local variable should be Initialized* before Utilization.	Defination:-Any variable which is declared outside* the method and inside the class is called as local variable. The scope of Global variable is from the begining of class still end of the class. It will have default value. It can be classified into Static or Non-Static.* Once the global vaiable is declared immeduately in next line it cannot initialize or reinitialize* it will throw Compile Time Error(CTE)

1)Local Variables

2)Global Variables

*Defination:-Any variable which is declared within the method is called as local variable.

*The scope of local variable is from the begining of method still end of the method.

*It will not have default value.

*It cannot be classified into Static or Non-Static.

*Local variable should be Initialized before Utilization.

*Defination:-Any variable which is declared outside the method and inside the class is called as local variable.

*The scope of Global variable is from the begining of class still end of the class.

*It will have default value.

*It can be classified into Static or Non-Static.

*Once the global vaiable is declared immeduately in next line it cannot initialize or reinitialize it will throw Compile Time Error(CTE)

⭐Default Values,Range,Size:-

Primitive Datatype	Default Values	Size(in bit's)	Range
byte	0	8	-128 to 127
short	0	16	-32,768 to 32,767
int	0	32	-2³¹ to 2 ³¹-1
long	0	64	-2⁶³ to 2 ⁶³-1
float	0.0f	32	1.4e-045 to 3.4e+038
double	0.0d	64	4.9e-324 to to 1.8e+308
char	\000000 OR Unicode	16	0 to 65,535
boolean	false	1	true or false
String	null

⭐Final Variable

Any Variable declares with a keyword final is called final variable.
Note:- Final Variable's cannot be re-initialized.