Data Types_premitive

Java Data Types  Variables are nothing but reserved memory locations to store values. This means that when you create a variable you reserve some space in memory Based on the data type of a variable, the operating system allocates memory and decides what can be stored in the reserved memory. Therefore, by assigning different data types to variables, you can store integers, decimals, or characters in these variables

There are two data types available in Java:

• Primitive Data Types
• Reference/Object Data Types 

Primitive Data Types:  There are eight primitive data types supported by Java. Primitive data types are predefined by the language and named by a keyword.

Sample Program :

public class DataTypesde

{

          public static void main(String[] args)

          {

// int

                   int i=10;

                   System.out.println(i);     //10

                   System.out.println(Integer.MAX_VALUE);         //2147483647

                   System.out.println(Integer.MIN_VALUE);                    //-2147483648

                   System.out.println(Integer.SIZE);                             //32

// double

                   double d=20.9;

                   double d1=20;

          System.out.println(d);                                                      //20.9

          System.out.println(d1);                                                    //20.0

          System.out.println(Double.MAX_VALUE);                //1.7976931348623157E308

          System.out.println(Double.MIN_VALUE);                 //4.9E-324

          System.out.println(Double.SIZE);                            //64

//char

          char c='a';

          char c2='d';

          System.out.println(c);                                                      //a

          System.out.println(c2);                                                    //b

          System.out.println(Character.MAX_CODE_POINT);   //1114111

          System.out.println(Character.MAX_VALUE);           //

          System.out.println(Character.MAX_VALUE);

    System.out.println(Character.SIZE);                              //16

          // string

          String s1="anji";                                                              //anji

          System.out.println(s1);

// float

          float f=10;

          float f2=10;

          System.out.println(Float.MAX_VALUE);                   //3.4028235E38

          System.out.println(Float.MIN_VALUE);           //1.4E-45

          System.out.println(Float.SIZE);                               //32

          System.out.println(f);                                                       //10.0

// byte

          byte b1=10;

          System.out.println(b1);                                           //10

          System.out.println(Byte.SIZE);                      //8

          System.out.println(Byte.MAX_VALUE);          //127

          System.out.println(Byte.MIN_VALUE);            //-128

//short

      short sh=25;

       System.out.println(sh);                                    //25

       System.out.println(Short.MAX_VALUE);  //32767

       System.out.println(Short.MIN_VALUE);   //-32768

       System.out.println(Short.SIZE);              //16

// long

    long t=123;

    System.out.println(t);                               //123

    System.out.println(Long.MAX_VALUE);      //9223372036854775807

    System.out.println(Long.MIN_VALUE);       //-9223372036854775808

    System.out.println(Long.SIZE);                  //64

          }

}

Data types and default size:

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