Data Types In Java

Primitive Data Types and Referenced Datatypes

Premitive Data Types:
 There are  eight primitive data types in Java
"boolean"  :- the type whose values are either true or false
"char" :- the character type whose values are 16-bit Unicode characters (only single character ).
ex: 'a'
The arithmetic types:
The integral types:
"byte" (-128 .. 127 numeric range values)
"short"(-32,768 .. 32,767 numeric range values)
"int"(-2,147,483,648 .. 2,147,483,647 numeric range values )
"long"(-9,223,372,036,854,775,808 .. 9,223,372,036,854,775,807 numeric range values )
The floating-point types
"float"
"double"

Referenced Datatypes:
Referenced DataType is a varible defined  of a class
for example : "String" is a class given in "java.lang" package
if we want to represent a string (a group of characters) i.e"abcdef"

we need to define a variable of String class type as below
String str = "abc";

ReferenceType for custom class:
if we have a class Defined as bellow
class Vehicle{
int vehicleNo;
String vehicleName;
String vehicleCompany;

}

if we want to hold a vehicle we can hold by help of reference type as bellow
Vehicle veh;
syntax:
class-name ref-variable ;

Default value:
default value means if we define a variable in a class and not assigned any value then there will be one value assigned to that variable that is default value , it is varying from type to type below are default values of every data type.

"String or any reference (predefined class or our own class)" Variable will have "null" as default value