Portfolio.java

import java.util.HashMap;
import java.util.Map;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Map;

public class Portfolio {

    private HashMap<String, Integer> holdings;

    // Constructor
    public Portfolio() {
        holdings = new HashMap<>();
    }

    // Add shares after buying
    public void addStock(String symbol, int quantity) {
        holdings.put(
            symbol,
            holdings.getOrDefault(symbol, 0) + quantity
        );
    }

    // Remove shares after selling
    public boolean removeStock(String symbol, int quantity) {

        int currentQuantity = holdings.getOrDefault(symbol, 0);

        if (currentQuantity < quantity) {
            return false;
        }

        int remaining = currentQuantity - quantity;

        if (remaining == 0) {
            holdings.remove(symbol);
        } else {
            holdings.put(symbol, remaining);
        }

        return true;
    }

    // Get number of shares owned
    public int getQuantity(String symbol) {
        return holdings.getOrDefault(symbol, 0);
    }

    // Check if portfolio is empty
    public boolean isEmpty() {
        return holdings.isEmpty();
    }

    // Display portfolio
    public void displayPortfolio(ArrayList<Stock> stocks) {

        if (holdings.isEmpty()) {
            System.out.println("Your portfolio is empty.");
            return;
        }

        System.out.println("\n============== MY PORTFOLIO ==============");
        System.out.printf("%-10s %-15s %-10s %-15s%n",
                "Symbol", "Company", "Quantity", "Value");
        System.out.println("------------------------------------------");

        double totalValue = 0;

        for (Map.Entry<String, Integer> entry : holdings.entrySet()) {

            String symbol = entry.getKey();
            int quantity = entry.getValue();

            for (Stock stock : stocks) {

                if (stock.getSymbol().equalsIgnoreCase(symbol)) {

                    double value = quantity * stock.getPrice();
                    totalValue += value;

                    System.out.printf(
                            "%-10s %-15s %-10d ₹%.2f%n",
                            symbol,
                            stock.getName(),
                            quantity,
                            value
                    );

                    break;
                }
            }
        }

        System.out.println("------------------------------------------");
        System.out.printf("Total Portfolio Value: ₹%.2f%n", totalValue);
        System.out.println("==========================================");
    }
}