Java Data Types

18-Sep-2024

Explore the different data types in Java for handling various types of data.

Java has several built-in data types that are used to define the types of data that variables can hold.
Java data types can be divided into two main groups: primitive data types and reference data types.

Primitive data types:

Numeric Types: Numeric Data types can not store fractions or decimal numbers.

Bytes:

8-bit signed integer. It is the smallest integer data type. It can store -128 to 127.

Syntax: byte byteVariableName;

Short:

16-bit signed integer. It can store -32768 to 32767.

Syntax: short shortVariableName;

int:

32-bit signed integer. It can store 2147483648 (-2^31) to 2147483647 (2^31 -1).

Syntax: int intVariableName;

long:

64-bit signed Integer. It can store -9223372036854775808(-2^63) to 9223372036854775807(2^63 -1).

Syntax: long longVariableName;

Floating point Type: It can store fractions or decimal data.

Float:

32-bit floating point. It can have a 7-digit decimal precision and the value ends with f or F like 343.345f or 235.234F. it can store

1.4e-045 to 3.4e+038

Syntax: float floatVariableName;

double:

64-bit floating point. It can have a 15-digit decimal precision.

it can store 4.9e-324 to 1.8e+308

Syntax: double doubleVariableName;

Character type:

char:

16-bit Unicode character. It can only store a single character like a, b, H, s, etc. It can store lowercase and uppercase also. When assigned a char value must be enclosed in single quotes. We can store multiple language characters like English, Hindi, Bangla, etc.

Boolean type:

Boolean:

represents a Boolean value (true or false). it can store only true or false.

Non-Primitive data types or

Reference data types:

Object types:

These include the classes and interfaces you create, as well as built-in types such as String.

Array Types:

Arrays can contain elements of any data type, including primitive types and reference types. Arrays can store multiple data of the same type separated by commas (, ).

String Types:

String is a collection of characters. When assigned a char value must be enclosed in double quotes. We can store multiple language characters like English, Hindi, Bangla, etc.

Default value:

byte: 0

short: 0

int: 0

long: 0

float: 0.0f

double 0.0d

char: \u0000

boolean: false


// Primitive Data Types
byte b = 127;
short s = 32767;
int i = 2147483647;
long l = 9223372036854775807L; // Note the 'L' at the end to specify a long literal
float f = 3.14f; // Note the 'f' at the end to specify a float literal
double d = 3.14159;

char c = 'A';

boolean isJavaFun = true;

// Reference Data Types
String greeting = "Hello, World!";
int[] array = {1, 2, 3, 4, 5};