Java Programming for Beginners Tutorial:1 Primitive vs Reference Data Types

In Java, data types are categorised into two main types: Primitive and Reference data types. Here's a breakdown of both:

1. Primitive Data Types
Primitive data types are the most basic type of data in Java. They represent single values and are not objects. They are stored directly in memory. Java has 8 primitive data types:

byte: 8-bit signed integer (-128 to 127)
short: 16-bit signed integer (-32,768 to 32,767)
int: 32-bit signed integer (-2^31 to 2^31-1)
long: 64-bit signed integer (-2^63 to 2^63-1)
float: 32-bit floating point (single precision)
double: 64-bit floating point (double precision)
char: 16-bit Unicode character (0 to 65,535)
boolean: Represents either true or false

Key Characteristics of Primitive Data Types:
Stored in stack memory.
Directly hold their data values.
Faster and more efficient in terms of memory usage.
Can be used for arithmetic and logical operations.

2. Reference Data Types
Reference data types are used to store references (or addresses) to objects. These are more complex types and can store data like arrays, strings, and instances of user-defined classes.
String: Represents a sequence of characters (although it's a class, it behaves like a primitive in many ways).
Arrays: A collection of elements of the same type.
Objects: Instances of classes, which can represent complex data and behaviours.

Key Characteristics of Reference Data Types:
Stored in heap memory (not stack memory).
Store the reference (memory address) to the object rather than the data itself.
Can store multiple values or complex structures like objects and arrays.
May have null values, meaning no object is assigned to the reference.