Java - variables , data types

Data Types

Data types in Java are classified in to types:

1. Primitive - which include Integer, Character, Boolean and Floating Point
2. Non-primitive - which includes Classes, Interfaces and Arrays

Integer:

• byte 1 byte
• short 2 bytes
• int 4 bytes
• long 8 bytes

Floating Point: number + fractional parts 

• float
• double

Character: stores character

Boolean: hold true false value

Variables 

Instance Variables (non-Static Fields) - Objects store their individual states in “non-static fields”, that is, fields declared without the static keyword.

Class Variables - Static Fields - any field with static modifier says that there is only one copy of this variable in existence static int myClassVariable = 6; 

Local Variables - a method stores it's temporary state of local variables int count=0;

Parameters - variables which will be passed to the methods of a class