Day Two: Variables, Data Types & Operators

Variables in Java

Variables are containers for storing data values. In Java, there are different types of variables:

• Primitive variables - store simple values
• Reference variables - store addresses of objects

Variable Declaration Syntax:

dataType variableName = value;

Example:

int age = 25;
double salary = 50000.50;
boolean isEmployed = true;
char grade = 'A';
String name = "John Doe";

Data Types in Java

Primitive Data Types:

Reference Data Types:

Reference types store references to objects. The most common reference type is:

• String - stores text, e.g., String name = "John";
• Arrays - stores collections of values, e.g., int[] numbers = {1, 2, 3};
• Classes - user-defined types, e.g., Person person = new Person();