Java Variables and Data Types

Variables in Java are containers for storing data values. Every variable must have a data type.

Primitive Data Types

• byte, short, int, long (integer types)
• float, double (floating-point types)
• char (character type)
• boolean (true/false)

Example

int age = 25;
double price = 19.99;
char grade = 'A';
boolean isActive = true;

Reference Data Types

• Strings: String name = "Java";
• Arrays: int[] numbers = {1, 2, 3};
• Objects: Instances of classes

Type Conversion

int x = 10;
double y = x; // Implicit conversion (int to double)
double z = 9.8;
int w = (int) z; // Explicit casting (double to int)