Hey everyone! We're starting again from Day 1 so everyone can build a strong foundation by learning everything from the basics this time.

🎉 **Day 1: Introduction to Java with Hello World!** 🎉

👋 Welcome to the very first day of our exciting Java Learning Series! 🚀 Today, we're taking our initial steps into the powerful world of Java programming. We'll start with the absolute basics: understanding the structure of a simple Java program and making it say that classic greeting: "Hello, World!" Get ready to write your first lines of code and witness them in action! Let's dive in! 💻

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**Your First Java Code:**

Here's the quintessential "Hello World" program in Java. Don't worry if it looks a bit complex at first; we'll break down each part in future lessons!

```java
public class HelloWorld {
public static void main(String[] args) {
// This line prints "Hello, World!" to the console
System.out.println("Hello, World!");
}
}
```

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**Output example:**
```
Hello, World!
```

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**💡 Small Challenge for You!**

Your first programming challenge: Can you modify the line `System.out.println("Hello, World!");` in the code above to print "Hello, [Your Name]!" instead? Give it a try and see your personalized message appear in the console! 🤔 Share your output in the comments!

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Day 1: Introduction to Java with Hello World \- Code & Output

🚀 Day 2: Variables and Data Types! 🚀

Ready to store information in your Java programs? Today, we dive into the fundamental concepts of Variables and Data Types. Think of variables as named containers for different kinds of data, from numbers to text and true/false values. Understanding them is key to writing dynamic and powerful code! Let's get started and see how Java handles different types of information. 💡📚

```java
public class Day2Variables {
public static void main(String[] args) {
// Declaring and initializing different types of variables

// 1. Integer (whole numbers)
int age = 30;
System.out.println("My age is: " + age); // Output: My age is: 30

// 2. Double (floating-point numbers, e.g., decimals)
double price = 19.99;
System.out.println("The product price is: $" + price); // Output: The product price is: $19.99

// 3. Boolean (true or false)
boolean isJavaFun = true;
System.out.println("Is Java fun? " + isJavaFun); // Output: Is Java fun? true

// 4. Character (single character)
char initial = 'J';
System.out.println("My initial is: " + initial); // Output: My initial is: J

// 5. String (sequence of characters - technically a class, but acts like a primitive for beginners)
String userName = "CodeMaster7";
System.out.println("Username: " + userName); // Output: Username: CodeMaster7

// You can also change variable values
age = 31; // Age is now updated
System.out.println("Updated age: " + age); // Output: Updated age: 31

// Simple arithmetic with variables
int num1 = 10;
int num2 = 5;
int sum = num1 + num2;
System.out.println("Sum of " + num1 + " and " + num2 + " is: " + sum); // Output: Sum of 10 and 5 is: 15
}
}
```

Output example:
```
My age is: 30
The product price is: $19.99
Is Java fun? true
My initial is: J
Username: CodeMaster7
Updated age: 31
Sum of 10 and 5 is: 15
```

✨ **Your Small Challenge:**
Create a new Java program. Declare a `float` variable (remember to add 'f' at the end of the number, e.g., `3.14f`) to store the value of Pi. Then, declare an `int` variable for a radius. Calculate the area of a circle (`Pi * radius * radius`) and print the result to the console! Don't forget to use appropriate data types for your variables. Good luck! 🎯

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Day 2: Variables and Data Types \- Code & Output