Create Java code for a Laptop class that implements a StockInfo interface and tracks the total number of laptops created.

// StockInfo.java
public interface StockInfo {
    void displayStockDetails();
}

// Laptop.java
public class Laptop implements StockInfo {
    private String brand;
    private int ramSizeGB;
    private double price;
    private static int totalLaptopsCreated = 0; // Static variable to count laptops

    // Constructor
    public Laptop(String brand, int ramSizeGB, double price) {
        this.brand = brand;
        this.ramSizeGB = ramSizeGB;
        this.price = price;
        totalLaptopsCreated++; // Increment count when a new laptop is created
    }

    // Implement the interface method
    @Override
    public void displayStockDetails() {
        System.out.println("Brand: " + brand);
        System.out.println("RAM Size: " + ramSizeGB + "GB");
        System.out.println("Price: $" + String.format("%.2f", price));
    }

    // Static method to get the total number of laptops
    public static int getTotalLaptopsCreated() {
        return totalLaptopsCreated;
    }
}

// Main.java
public class Main {
    public static void main(String[] args) {
        // Create three laptop objects
        Laptop laptop1 = new Laptop("Dell", 16, 1200.50);
        Laptop laptop2 = new Laptop("HP", 8, 850.00);
        Laptop laptop3 = new Laptop("Apple", 16, 1800.75);

        System.out.println("--- Laptop Details ---");
        laptop1.displayStockDetails();
        System.out.println("--------------------");
        laptop2.displayStockDetails();
        System.out.println("--------------------");
        laptop3.displayStockDetails();
        System.out.println("--------------------");

        // Display the total number of laptops created
        System.out.println("Total number of laptops created: " + Laptop.getTotalLaptopsCreated());
    }
}

--- Laptop Details ---
Brand: Dell
RAM Size: 16GB
Price: $1200.50
--------------------
Brand: HP
RAM Size: 8GB
Price: $850.00
--------------------
Brand: Apple
RAM Size: 16GB
Price: $1800.75
--------------------
Total number of laptops created: *3*

// Shape.java
public abstract class Shape {
    // Abstract method to calculate area
    public abstract double calculateArea();
}

// Circle.java
public class Circle extends Shape {
    private double radius;

    // Constructor
    public Circle(double radius) {
        this.radius = radius;
    }

    // Implement the abstract method to calculate area for a circle
    @Override
    public double calculateArea() {
        return Math.PI * radius * radius;
    }

    // Optional: Getter for radius
    public double getRadius() {
        return radius;
    }
}

// Main.java
public class Main {
    public static void main(String[] args) {
        // Create a Circle object with radius 5.0
        Circle circle = new Circle(5.0);

        // Display the computed area
        System.out.println("Circle Radius: " + circle.getRadius());
        System.out.println("Computed Area: " + String.format("%.2f", circle.calculateArea()));
    }
}

Circle Radius: 5.0
Computed Area: *78.54*

// CourseDisplay.java
public interface CourseDisplay {
    void displayCourseDetails();
}

// Course.java
public class Course implements CourseDisplay {
    private String courseCode;
    private String courseName;
    private int creditHours;

    // Constructor
    public Course(String courseCode, String courseName, int creditHours) {
        this.courseCode = courseCode;
        this.courseName = courseName;
        this.creditHours = creditHours;
    }

    // Access methods (Getters)
    public String getCourseCode() {
        return courseCode;
    }

    public String getCourseName() {
        return courseName;
    }

    public int getCreditHours() {
        return creditHours;
    }

    // Access methods (Setters - optional, but good practice for "access methods")
    public void setCourseCode(String courseCode) {
        this.courseCode = courseCode;
    }

    public void setCourseName(String courseName) {
        this.courseName = courseName;
    }

    public void setCreditHours(int creditHours) {
        this.creditHours = creditHours;
    }

    // Implement the interface method
    @Override
    public void displayCourseDetails() {
        System.out.println("Course Code: " + courseCode);
        System.out.println("Course Name: " + courseName);
        System.out.println("Credit Hours: " + creditHours);
    }
}

// Main.java
public class Main {
    public static void main(String[] args) {
        // Create two Course objects
        Course course1 = new Course("CS101", "Introduction to Programming", 3);
        Course course2 = new Course("MA201", "Calculus I", 4);

        System.out.println("--- Course 1 Details ---");
        course1.displayCourseDetails();
        System.out.println("------------------------");

        System.out.println("--- Course 2 Details ---");
        course2.displayCourseDetails();
        System.out.println("------------------------");
    }
}

--- Course 1 Details ---
Course Code: CS101
Course Name: Introduction to Programming
Credit Hours: 3
------------------------
--- Course 2 Details ---
Course Code: MA201
Course Name: Calculus I
Credit Hours: 4
------------------------

// Person.java
public abstract class Person {
    private String name;
    private int age;

    // Constructor
    public Person(String name, int age) {
        this.name = name;
        this.age = age;
    }

    // Getters
    public String getName() {
        return name;
    }

    public int getAge() {
        return age;
    }

    // Abstract method for checking eligibility
    public abstract boolean checkEligibility();
}

// Member.java
public class Member extends Person {
    private String membershipType; // e.g., "Standard", "Premium"

    // Constructor
    public Member(String name, int age, String membershipType) {
        super(name, age); // Call the constructor of the superclass (Person)
        this.membershipType = membershipType;
    }

    // Getter for membershipType
    public String getMembershipType() {
        return membershipType;
    }

    // Implement the abstract method for eligibility check
    // Members aged 60 and above qualify for a discount
    @Override
    public boolean checkEligibility() {
        return getAge() >= 60;
    }

    public void displayMemberDetails() {
        System.out.println("Name: " + getName());
        System.out.println("Age: " + getAge());
        System.out.println("Membership Type: " + membershipType);
        System.out.println("Eligible for Senior Discount: " + (checkEligibility() ? "Yes" : "No"));
    }
}

// Main.java
public class Main {
    public static void main(String[] args) {
        // Create a member who qualifies for a discount
        Member seniorMember = new Member("John Doe", 65, "Gold");
        System.out.println("--- Senior Member Details ---");
        seniorMember.displayMemberDetails();
        System.out.println("-----------------------------");

        // Create a member who does not qualify
        Member regularMember = new Member("Jane Smith", 30, "Silver");
        System.out.println("--- Regular Member Details ---");
        regularMember.displayMemberDetails();
        System.out.println("------------------------------");

        // Create a member at the age threshold
        Member thresholdMember = new Member("Peter Jones", 60, "Bronze");
        System.out.println("--- Threshold Member Details ---");
        thresholdMember.displayMemberDetails();
        System.out.println("--------------------------------");
    }
}

--- Senior Member Details ---
Name: John Doe
Age: 65
Membership Type: Gold
Eligible for Senior Discount: *Yes*
-----------------------------
--- Regular Member Details ---
Name: Jane Smith
Age: 30
Membership Type: Silver
Eligible for Senior Discount: *No*
------------------------------
--- Threshold Member Details ---
Name: Peter Jones
Age: 60
Membership Type: Bronze
Eligible for Senior Discount: *Yes*
--------------------------------