Data Types

1. Primitive Data Types: These data types represent single values and are not objects.

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

2. Reference Data Types: These data types are used to create objects and reference them. These include:

   • Classes: User-defined data types.
   • Interfaces: Defines a contract for classes to implement.
   • Arrays: A collection of elements of the same data type.

3. Wrapper Classes: These are classes that provide a way to use primitive data types as objects. They include:

   • Byte
   • Short
   • Integer
   • Long
   • Float
   • Double
   • Character
   • Boolean

4. Enumeration (Enum): An enumeration is a special type used to define a collection of constants.

5. String: Java has a built-in class called String to work with text as a sequence of characters.

6. User-Defined Data Types: Java allows you to create your own data types using classes and interfaces. These can be quite complex and tailored to the needs of your program.

7. Array Types: You can create arrays of any data type. For example, you can have an array of integers, an array of strings, and so on.

8. Generics: Java supports generics, which allow you to create classes, interfaces, and methods that operate on typed parameters. Generics enable you to create more flexible and type-safe data structures and algorithms.

9. Null Type: There is a special type in Java called null, which represents the absence of a value. It is used for variables that don't currently reference any object.

10. Custom Data Types: You can define your own custom data types by creating classes and structures tailored to your specific application needs.