Java HashMap compute()

Java HashMap [Java HashMap] Java HashMap

compute() hashMap key

compute() 

hashmap.compute(K key, BiFunction remappingFunction)

hashmap HashMap

  • key -
  • remappingFunction -

key value null remappingFunction

compute()

import java.util.HashMap;

class Main {
    public static void main(String[] args) {
        // HashMap
        HashMap<String, Integer> prices = new HashMap<>();

        // HashMap
        prices.put("Shoes", 200);
        prices.put("Bag", 300);
        prices.put("Pant", 150);
        System.out.println("HashMap: " + prices);

        // 10%
        int newPrice = prices.compute("Shoes", (key, value) -> value - value * 10/100);
        System.out.println("Discounted Price of Shoes: " + newPrice);

        // HashMap
        System.out.println("Updated HashMap: " + prices);
    }
}

HashMap: {Pant=150, Bag=300, Shoes=200}
Discounted Price of Shoes: 180
Updated HashMap: {Pant=150, Bag=300, Shoes=180

prices HashMap

prices.compute("Shoes", (key, value) -> value - value * 10/100)

lambda (key, value) -> value - value * 10/100

lambda Java Lambda

Java HashMap [Java HashMap] Java HashMap