Java Data Types

Primitive Data Types

Primitive data types are the most basic data types available within the Java language. They serve as the building blocks of data manipulation in Java. There are 8 primitive data types.

Data Type	Description	Default Value	Size
byte	Signed integer	0	1 byte
short	Signed integer	0	2 bytes
int	Signed integer	0	4 bytes
long	Signed integer	0L	8 bytes
float	Single-precision floating point	0.0f	4 bytes
double	Double-precision floating point	0.0d	8 bytes
boolean	Represents true or false values	false	1 bit
char	A single Unicode character	'\u0000'	2 bytes

Reference (Non-Primitive) Data Types

Reference data types are created by programmers and are not defined by Java (except for String). They refer to objects. The main difference between primitive and reference data types is that primitive types store the actual values, whereas reference types store the address where the value is being stored.

Strings

In Java, a string is an object that represents a sequence of characters.

Arrays

An array is a container object that holds a fixed number of values of a single type.

Classes

A class is a blueprint from which individual objects are created.

Interfaces

An interface is a reference type in Java. It is a collection of abstract methods.