Variable and Datatype in Java

Variable and Datatype in Java

In this page, we will learn about the variable and java data types. Variable is a name of memory location.There are three types of variables: local, instance and static. There are two types of datatypes in java, primitive and non-primitive.


Variable
 
Variable is name of reserved area allocated in memory.



int data=50;//Here data is variable

Types of Variable

There are three types of variables in java

• local variable
• instance variable
• static variable

Local Variable

A variable that is declared inside the method is called local variable.
 
Instance Variable

A variable that is declared inside the class but outside the method is called instance variable . It is not declared as static.
 
Static variable

A variable that is declared as static is called static variable. It cannot be local.We will have detailed learning of these variables in next chapters.

Example to understand the types of variables
class A{
int data=50;//instance variable
static int m=100;//static variable
void method(){
int n=90;//local variable
}
}//end of class

Data Types in Java

In java, there are two types of data types

• primitive data types
• non-primitive data types

Data Type        Default Value      Default size
boolean                  false              1  bit
char                   '\u0000'             2 byte 
byte                        0                  1 byte
short                       0                  2 byte
int                           0                  4 byte
long                        0L                8 byte
float                        0.0f              4 byte
double                    0.0d              8 byte