What are the 2 types of variables in Java?

In Java, variables are classified into different types based on the kind of data they can store. The variable types in Java can be broadly categorized into two groups: primitive data types and reference data types.

Primitive Data Types:

Primitive data types represent the most basic data types available in Java. They are used to store simple values. There are eight primitive data types in Java:

byte: 8-bit signed integer
short: 16-bit signed integer
int: 32-bit signed integer
long: 64-bit signed integer
float: 32-bit floating-point number
double: 64-bit floating-point number
char: 16-bit Unicode character
boolean: Represents true or false values

Example of primitive variable declaration:

int age = 25;
double salary = 50000.50;
char grade = 'A';
boolean isStudent = true;

Reference Data Types:

Reference data types are used to store references or addresses of objects. They include:

Classes: User-defined types
Interfaces: Blueprint of classes
Arrays: Homogeneous collections of elements

Example of reference variable declaration:

String name = "John";
Object obj = new Object(); // Object is a class in Java
int[] numbers = {1, 2, 3, 4, 5}; // Array of integers

It's important to note that primitive data types store actual values, whereas reference data types store references to objects in memory.