Java has two types of data types - primitive and non-primitive. Primitive types include integer, character, boolean, and floating point types like float and double which are used to represent numbers with decimals. Non-primitive types include classes, interfaces, and arrays. A variable in Java is a memory location that can store a value, and there are different types of variables including instance variables, class variables, local variables, and parameters. Variables are declared with a data type and name, and can be initialized with a value.

1. Java Tutorial
Data Types and Variables

2. Content
• What is Data Type in Java
• What is Variable

3. What is Data Type in Java
• Data type specifies the size and type of values that can be stored in
an identifier.
• Data types in Java are classified into two types:
• Primitive
• Non-primitive

4. Primitive Data Types
• Integer
• Character
• Boolean
• Floating Point

5. Non-primitive
• Classes
• Interfaces
• Arrays

6. Integer
• Integer types can hold whole numbers such as 123 and −96. The size
of the values that can be stored depends on the integer type that
we choose.
• Byte
• Short
• Int
• long

7. Floating Point
• Floating point data types are used to represent numbers with a
fractional part
• float
• double

8. Character
• It stores character constants in the memory.
• char

9. Boolean
• Boolean data types are used to store values with two states:
• true
• false.

10. What is Variable
• A Java variable is a piece of memory that can contain a data value
• There are different types of variables in Java. They are as follows:
• Instance Variables (Non-Static Fields)
• Class Variables (Static Fields)
• Local Variables
• Parameters

11. Variable Declaration
• Syntax for variable declaration
datatype1 variable1, datatype2 variable2, … datatypen variablen;
• For Example
• int a; char ch;
•Initialization
• a = 10;
• ch = ‘A’;