HashMap examples: To check a product is available in the list or not.

              Let us create this program using hashMap.  A list of products with its prices are added to the hashMap.

Steps:

• ·       Import the built-in packages java.util.HashMap,java.util.Map.
• ·       A public class is developed with main() function.
• ·       Constructor: initializes the object.
• ·       addItems() : it inserts the product and price.
• ·       getPrice() : This function gets the price for the product.
• ·       updatePrice(): it updates the price.
• ·       printPrice() : This function prints the product and price.

Program:

// import the built-in packages

import java.util.HashMap;

import java.util.Map;

//Create a public class

public class ProductPricesPrint {

    private Map<String, Double> prices;

//constructor of the class to initialise the object.

    public ProductPricesPrint() {

        prices = new HashMap<>();

    }

//Member function addItem()

    public void addItem(String Product, double price) {

        prices.put(Product, price);

    }

//Member function getPrice()

    public Double getPrice(String Product) {

        return prices.get(Product);

    }

//updatePrice() function to update the value.

    public void updatePrice(String Product, double newPrice) {

        if (prices.containsKey(Product)) {

            prices.put(Product, newPrice);

        }

    }

//To print the product list

    public void printPrice(String Product) {

        Double price = prices.get(Product);

        if (price != null) {

            System.out.println("The price of " + Product + " is: " + price);

        } else {

            System.out.println(Product + " is not available.");

        }

    }

//Main() function definition

    public static void main(String[] args) {

        ProductPricesPrint productPricesPrint = new ProductPricesPrint();

    

        productPricesPrint.addItem("Cricket bat", 1500);

        productPricesPrint.addItem("Cricket ball",200);

        productPricesPrint.addItem("Hockey Bat",1000);

        productPricesPrint.addItem("Hockey Ball",240);

        productPricesPrint.addItem("FootBall",500);

        productPricesPrint.addItem("BasketBall",450);

      //To check the product in the HashMap

        productPricesPrint.printPrice("BasketBall");

        productPricesPrint.printPrice("carrom");

    }

}

Output:

C:\raji\blog>javac ProductPricesPrint.java

C:\raji\blog>java ProductPricesPrint.java

The price of BasketBall is: 450.0

carrom is not available.

This is the way of checking a product list is available in the list or not. Keep coding!!!