DataTypes in Java

DataTypes are of two types;
Primitive and Non-Primitive

Primitive data types:
boolean, byte, int, char, short, long, double, float

Non-Primitive data types:
String, Array, Class, Interface

Default Values

boolean	//Defaultvalue=false
byte	//Defaultvalue=0
int	//Defaultvalue=0
char	//Defaultvalue='\u0000'
String	//Defaultvalue=null
short	//Defaultvalue=0
long	//Defaultvalue=0L
double	//Defaultvalue=0.0d
float	//Defaultvalue=0.0f
Size and Range
boolean	//size=1bit	//range:
byte	//size=8bits(1byte)	//range:-2tothepower(8-1)to+2tothepower8-1
int	//size=32bits(4bytes)	//range:-2tothepower(32-1)to+2tothepower32-1
char	//size=16bits(2bytes)	//range:-2tothepower(16-1)to+2tothepower16-1
short	//size=16bits(2bytes)	//range:-2tothepower(16-1)to+2tothepower16-1
long	//size=64bits(8bytes)	//range:-2tothepower(64-1)to+2tothepower64-1
double	//size=64bits(8bytes)	//range:-2tothepower(64-1)to+2tothepower64-1
float	//size=32bits(4bytes)	//range:-2tothepower(32-1)to+2tothepower32-1

In Non-Primitive datatypes, you create reference object of the String , Array or Class.

String[] string = new String[20]; // This is example of String +Array. Click here for detail about string array.

Class objectReference = new Class();

 

Below code finds the default value of each variables:

package heloWorld;

public class DataTypes {

            static boolean bl;  

            static byte bt;      

            static int it;       

            static char chr;     

            static String str;                                                        

            static short shrt;  

            static long lng;     

            static double dble;  

            static float fl;    

           

            public static void main(String[] args) {

                        System.out.println("Default value of boolean = "+bl);

                        System.out.println("Default value of byte = "+bt);

                        System.out.println("Default value of int = "+it);

                        System.out.println("Default value of char = "+chr);

                        System.out.println("Default value of String = "+str);

                        System.out.println("Default value of short = "+shrt);

                        System.out.println("Default value of long = "+lng);

                        System.out.println("Default value of double = "+dble);

                        System.out.println("Default value of float = "+fl);

            }

}

OutPut: