/*
  ESP32 Variables & Data Types Demo
  - Uses Serial Monitor to show results (no hardware required)
*/

// Global Variables (accessible everywhere)
int studentAge = 18;            // Integer (whole numbers)
float temperature = 23.5;       // Float (decimal numbers)
char grade = 'B';               // Character (single letter)
bool isSunny = true;            // Boolean (true/false)
String message = "Hello ESP32!";// String (text)

void setup() {
  Serial.begin(115200); // Start serial communication

  // Print initial values
  Serial.println("--- Initial Values ---");
  Serial.print("Student Age (int): ");
  Serial.println(studentAge);
  Serial.print("Temperature (float): ");
  Serial.println(temperature);
  Serial.print("Grade (char): ");
  Serial.println(grade);
  Serial.print("Is it sunny? (bool): ");
  Serial.println(isSunny);
  Serial.print("Message (String): ");
  Serial.println(message);
  Serial.println("-----------------------");
}

void loop() {
  // Modify variables
  studentAge += 1;           // Add 1 to age (integer math)
  temperature += 0.5;        // Increase temperature by 0.5
  grade = 'A';               // Change character
  isSunny = !isSunny;        // Toggle boolean
  message += " :)";          // Append to String

  // Print updated values
  Serial.println("\n--- Updated Values ---");
  Serial.print("New Age: ");
  Serial.println(studentAge);
  Serial.print("New Temperature: ");
  Serial.println(temperature);
  Serial.print("New Grade: ");
  Serial.println(grade);
  Serial.print("Is it sunny now? ");
  Serial.println(isSunny ? "YES" : "NO"); // Ternary operator
  Serial.print("New Message: ");
  Serial.println(message);
  Serial.println("-----------------------");

  delay(5000); // Wait 5 seconds before repeating
}