Data Types in Java

Java is a strongly-typed language, which means every variable must have a specific data type. Java's data types can be divided into two categories:

Primitive Data Types
Reference Data Types

Primitive Data Types

Primitive data types are the most basic data types in Java. They store simple values like numbers, characters, and booleans.

Data Type	Size	Default Value	Description	Example
byte	1 byte	0	Stores small integers from -128 to 127	byte a = 10;
short	2 bytes	0	Stores integers from -32,768 to 32,767	short b = 1000;
int	4 bytes	0	Stores integers from -2^31 to 2^31-1	int c = 50000;
long	8 bytes	0L	Stores large integers from -2^63 to 2^63-1	long d = 100000L;
float	4 bytes	0.0f	Stores floating-point numbers (single precision)	float e = 5.75f;
double	8 bytes	0.0d	Stores double-precision floating-point numbers	double f = 19.99d;
char	2 bytes	'\u0000'	Stores single 16-bit Unicode characters	char g = 'A';
boolean	1 bit	false	Stores `true` or `false`	boolean h = true;

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public class PrimitiveExample {    public static void main(String[] args) {        byte byteVar = 120;        short shortVar = 1000;        int intVar = 123456;        long longVar = 1000000000L;        float floatVar = 12.34f;        double doubleVar = 1234.56;        char charVar = 'J';        boolean boolVar = true;​        System.out.println("Byte value: " + byteVar);        System.out.println("Short value: " + shortVar);        System.out.println("Int value: " + intVar);        System.out.println("Long value: " + longVar);        System.out.println("Float value: " + floatVar);        System.out.println("Double value: " + doubleVar);        System.out.println("Char value: " + charVar);        System.out.println("Boolean value: " + boolVar);    }}

Output

Byte value: 120
Short value: 1000
Int value: 123456
Long value: 1000000000
Float value: 12.34
Double value: 1234.56
Char value: J
Boolean value: true

Reference Data Types

Reference data types refer to objects and arrays, not primitive values. They store references (addresses) to the actual objects in memory.

Examples:

String: Represents a sequence of characters.
Arrays: Represents a fixed-size collection of elements of the same type.
Objects: Instances of classes.

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public class ReferenceExample {    public static void main(String[] args) {        String name = "Java Programming";  // String is a reference type        int[] numbers = {1, 2, 3, 4, 5};   // Array is a reference type​        System.out.println("Name: " + name);        System.out.println("First number in the array: " + numbers[0]);    }}

Output

Name: Java Programming
First number in the array: 1

Data Types in Java

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