Beginner

Basics & Foundations

Start your Java journey by learning the fundamental building blocks of the language.

Topics

Variables & Data Types

Variables are containers for storing data values. In Java, every variable must have a data type.

Primitive Data Types

Type	Size	Description	Example
int	4 bytes	Whole numbers	int age = 25;
double	8 bytes	Decimal numbers	double price = 19.99;
boolean	1 bit	true or false	boolean isActive = true;
char	2 bytes	Single character	char grade = 'A';
String	varies	Text (not primitive)	String name = "John";

Example

public class Variables {
    public static void main(String[] args) {
        // Integer
        int age = 25;
        
        // Double (decimal)
        double price = 19.99;
        
        // Boolean
        boolean isStudent = true;
        
        // Character
        char grade = 'A';
        
        // String
        String name = "Alice";
        
        System.out.println("Name: " + name);
        System.out.println("Age: " + age);
        System.out.println("Price: $" + price);
        System.out.println("Is Student: " + isStudent);
        System.out.println("Grade: " + grade);
    }
}

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