LeelaRamani - Easy level tasks

Calculator.java

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+import java.util.Scanner;
+
+public class Calculator {
+    public static void main(String[] args) {
+        Scanner scanner = new Scanner(System.in);
+
+        System.out.println("Enter first number:");
+        double num1 = scanner.nextDouble();
+
+        System.out.println("Enter second number:");
+        double num2 = scanner.nextDouble();
+
+        System.out.println("Enter an operator (+, -, *, /):");
+        char operator = scanner.next().charAt(0);
+
+        double result;
+
+        switch (operator) {
+            case '+':
+                result = num1 + num2;
+                break;
+            case '-':
+                result = num1 - num2;
+                break;
+            case '*':
+                result = num1 * num2;
+                break;
+            case '/':
+                if (num2 != 0) {
+                    result = num1 / num2;
+                } else {
+                    System.out.println("Error! Division by zero.");
+                    return;
+                }
+                break;
+            default:
+                System.out.println("Error! Invalid operator.");
+                return;
+        }
+
+        System.out.println("The result is: " + result);
+        scanner.close();
+    }
+}

NumberGuessingGame.java

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+import java.util.Random;
+import java.util.Scanner;
+
+public class NumberGuessingGame {
+    public static void main(String[] args) {
+        Scanner scanner = new Scanner(System.in);
+        Random random = new Random();
+
+        int maxAttempts = 5;
+        int numberToGuess = random.nextInt(100) + 1;
+        int numberOfAttempts = 0;
+        boolean hasWon = false;
+
+        System.out.println("Welcome to the Number Guessing Game!");
+        System.out.println("I have selected a number between 1 and 100.");
+        System.out.println("You have " + maxAttempts + " attempts to guess it.");
+
+        while (numberOfAttempts < maxAttempts) {
+            System.out.print("Enter your guess: ");
+            int guess = scanner.nextInt();
+            numberOfAttempts++;
+
+            if (guess < numberToGuess) {
+                System.out.println("Too low!");
+            } else if (guess > numberToGuess) {
+                System.out.println("Too high!");
+            } else {
+                hasWon = true;
+                break;
+            }
+        }
+
+        if (hasWon) {
+            System.out.println("Congratulations! You've guessed the number in " + numberOfAttempts + " attempts.");
+        } else {
+            System.out.println("Sorry! You've used all your attempts. The number was " + numberToGuess + ".");
+        }
+
+        scanner.close();
+    }
+}

TaskManager.java

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+import java.util.ArrayList;
+import java.util.Scanner;
+
+class Task {
+    private String description;
+    private boolean isCompleted;
+
+    public Task(String description) {
+        this.description = description;
+        this.isCompleted = false;
+    }
+
+    public String getDescription() {
+        return description;
+    }
+
+    public boolean isCompleted() {
+        return isCompleted;
+    }
+
+    public void markAsCompleted() {
+        this.isCompleted = true;
+    }
+
+    @Override
+    public String toString() {
+        return (isCompleted ? "[X] " : "[ ] ") + description;
+    }
+}
+
+public class TaskManager {
+    private static ArrayList<Task> tasks = new ArrayList<>();
+    private static Scanner scanner = new Scanner(System.in);
+
+    public static void main(String[] args) {
+        boolean exit = false;
+        while (!exit) {
+            printMenu();
+            int choice = scanner.nextInt();
+            scanner.nextLine(); // Consume newline
+
+            switch (choice) {
+                case 1:
+                    addTask();
+                    break;
+                case 2:
+                    deleteTask();
+                    break;
+                case 3:
+                    markTaskAsCompleted();
+                    break;
+                case 4:
+                    listTasks();
+                    break;
+                case 5:
+                    exit = true;
+                    break;
+                default:
+                    System.out.println("Invalid choice. Please try again.");
+            }
+        }
+        scanner.close();
+    }
+
+    private static void printMenu() {
+        System.out.println("\nTask Manager:");
+        System.out.println("1. Add Task");
+        System.out.println("2. Delete Task");
+        System.out.println("3. Mark Task as Completed");
+        System.out.println("4. List Tasks");
+        System.out.println("5. Exit");
+        System.out.print("Choose an option: ");
+    }
+
+    private static void addTask() {
+        System.out.print("Enter task description: ");
+        String description = scanner.nextLine();
+        tasks.add(new Task(description));
+        System.out.println("Task added.");
+    }
+
+    private static void deleteTask() {
+        listTasks();
+        System.out.print("Enter task number to delete: ");
+        int taskNumber = scanner.nextInt();
+        scanner.nextLine(); // Consume newline
+        if (taskNumber > 0 && taskNumber <= tasks.size()) {
+            tasks.remove(taskNumber - 1);
+            System.out.println("Task deleted.");
+        } else {
+            System.out.println("Invalid task number.");
+        }
+    }
+
+    private static void markTaskAsCompleted() {
+        listTasks();
+        System.out.print("Enter task number to mark as completed: ");
+        int taskNumber = scanner.nextInt();
+        scanner.nextLine(); // Consume newline
+        if (taskNumber > 0 && taskNumber <= tasks.size()) {
+            tasks.get(taskNumber - 1).markAsCompleted();
+            System.out.println("Task marked as completed.");
+        } else {
+            System.out.println("Invalid task number.");
+        }
+    }
+
+    private static void listTasks() {
+        if (tasks.isEmpty()) {
+            System.out.println("No tasks available.");
+        } else {
+            System.out.println("Tasks:");
+            for (int i = 0; i < tasks.size(); i++) {
+                System.out.println((i + 1) + ". " + tasks.get(i));
+            }
+        }
+    }
+}

TemperatureConverter.java

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+import java.util.Scanner;
+
+public class TemperatureConverter {
+    public static void main(String[] args) {
+        Scanner scanner = new Scanner(System.in);
+
+        System.out.println("Enter the temperature value:");
+        double temperature = scanner.nextDouble();
+
+        System.out.println("Enter the scale to convert from (C, F, K):");
+        char fromScale = scanner.next().charAt(0);
+
+        System.out.println("Enter the scale to convert to (C, F, K):");
+        char toScale = scanner.next().charAt(0);
+
+        double convertedTemperature = 0.0;
+
+        switch (fromScale) {
+            case 'C':
+                convertedTemperature = convertFromCelsius(temperature, toScale);
+                break;
+            case 'F':
+                convertedTemperature = convertFromFahrenheit(temperature, toScale);
+                break;
+            case 'K':
+                convertedTemperature = convertFromKelvin(temperature, toScale);
+                break;
+            default:
+                System.out.println("Error! Invalid scale.");
+                return;
+        }
+
+        System.out.printf("The converted temperature is: %.2f %c%n", convertedTemperature, toScale);
+        scanner.close();
+    }
+
+    private static double convertFromCelsius(double temperature, char toScale) {
+        switch (toScale) {
+            case 'F':
+                return temperature * 9 / 5 + 32;
+            case 'K':
+                return temperature + 273.15;
+            case 'C':
+                return temperature;
+            default:
+                throw new IllegalArgumentException("Invalid scale: " + toScale);
+        }
+    }
+
+    private static double convertFromFahrenheit(double temperature, char toScale) {
+        switch (toScale) {
+            case 'C':
+                return (temperature - 32) * 5 / 9;
+            case 'K':
+                return (temperature - 32) * 5 / 9 + 273.15;
+            case 'F':
+                return temperature;
+            default:
+                throw new IllegalArgumentException("Invalid scale: " + toScale);
+        }
+    }
+
+    private static double convertFromKelvin(double temperature, char toScale) {
+        switch (toScale) {
+            case 'C':
+                return temperature - 273.15;
+            case 'F':
+                return (temperature - 273.15) * 9 / 5 + 32;
+            case 'K':
+                return temperature;
+            default:
+                throw new IllegalArgumentException("Invalid scale: " + toScale);
+        }
+    }
+}