Data types in Java are of different sizes and values that can be stored in the variable that is made as per convenience and circumstances to cover up all test cases. Java has two categories in which data types are segregated

Primitive Data Type: such as boolean, char, int, short, byte, long, float, and double
Non-Primitive Data Type or Object Data type: such as String, Array, etc.

Table of Contents

Primitive Data Type

Primitive data are only single values and have no special capabilities. There are 8 primitive data types. They are depicted below in tabular format below as follows:

Type	Description	Default	Size	Example Literals	Range of values
boolean	true or false	false	8 bits	true, false	true, false
byte	twos-complement integer	0	8 bits	(none)	-128 to 127
char	Unicode character	\u0000	16 bits	‘a’, ‘\u0041’, ‘\101’, ‘\\’, ‘\’, ‘\n’, ‘β’	characters representation of ASCII values 0 to 255
short	twos-complement integer	0	16 bits	(none)	-32,768 to 32,767
int	twos-complement intger	0	32 bits	-2,-1,0,1,2	-2,147,483,648 to 2,147,483,647
long	twos-complement integer	0	64 bits	-2L,-1L,0L,1L,2L	-9,223,372,036,854,775,808 to 9,223,372,036,854,775,807
float	IEEE 754 floating point	0.0	32 bits	1.23e100f , -1.23e-100f , .3f ,3.14F	upto 7 decimal digits
double	IEEE 754 floating point	0.0	64 bits	1.23456e300d , -123456e-300d , 1e1d	upto 16 decimal digits

Ex:

// Class
class Wrap {

    // Main driver method
    public static void main(String args[])
    {

        // Creating and initializing custom character
        char a = 'G';

        // Integer data type is generally
        // used for numeric values
        int i = 89;

        // use byte and short
        // if memory is a constraint
        byte b = 4;

        // this will give error as number is
        // larger than byte range
        // byte b1 = 7888888955;

        short s = 56;

        // this will give error as number is
        // larger than short range
        // short s1 = 87878787878;

        // by default fraction value
        // is double in java
        double d = 4.355453532;

        // for float use 'f' as suffix as standard
        float f = 4.7333434f;

        // need to hold big range of numbers then we need
        // this data type
        long l = 12121;

        System.out.println("char: " + a);
        System.out.println("integer: " + i);
        System.out.println("byte: " + b);
        System.out.println("short: " + s);
        System.out.println("float: " + f);
        System.out.println("double: " + d);
        System.out.println("long: " + l);
    }
}

// Class

class Wrap {

// Main driver method

public static void main(String args[])

{

// Creating and initializing custom character

char a = 'G';

// Integer data type is generally

// used for numeric values

int i = 89;

// use byte and short

// if memory is a constraint

byte b = 4;

// this will give error as number is

// larger than byte range

// byte b1 = 7888888955;

short s = 56;

// this will give error as number is

// larger than short range

// short s1 = 87878787878;

// by default fraction value

// is double in java

double d = 4.355453532;

// for float use 'f' as suffix as standard

float f = 4.7333434f;

// need to hold big range of numbers then we need

// this data type

long l = 12121;

System.out.println("char: " + a);

System.out.println("integer: " + i);

System.out.println("byte: " + b);

System.out.println("short: " + s);

System.out.println("float: " + f);

System.out.println("double: " + d);

System.out.println("long: " + l);

}

Output:

char: G
integer: 89
byte: 4
short: 56
float: 4.7333436
double: 4.355453532
long: 12121

char: G

integer: 89

byte: 4

short: 56

float: 4.7333436

double: 4.355453532

long: 12121

Non-Primitive Data Type or Reference Data Types

Non-primitive data types are called reference types because they refer to objects.

The main difference between primitive and non-primitive data types are:

Primitive types are predefined (already defined) in Java. Non-primitive types are created by the programmer and is not defined by Java (except for String).
Non-primitive types can be used to call methods to perform certain operations, while primitive types cannot.
A primitive type has always a value, while non-primitive types can be null.
A primitive type starts with a lowercase letter, while non-primitive types starts with an uppercase letter.

Examples of non-primitive types are Strings, Arrays, Classes, Interface, etc.