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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






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