ConcurrentHashMap values() method in Java with Examples
Last Updated : 30 Oct, 2018
The
values() method of
ConcurrentHashMap class in Java is used to create a collection out of the values of the map. It basically returns a Collection view of the values in the ConcurrentHashMap.
Syntax: ConcurrentHashMap.values()
Parameters: The method does not accept any parameters.
Return Value: The method is used to return a collection view containing all the values of the map. Below programs are used to illustrate the working of ConcurrentHashMap.values() Method:
Program 1: Mapping String Values to Integer Keys.
Java // Java code to illustrate the values() method import java.util.*; import java.util.concurrent.*; public class ConcurrentHashMapDemo { public static void main(String[] args) { // Creating an empty ConcurrentHashMap ConcurrentHashMap<Integer, String> hash_map = new ConcurrentHashMap<Integer, String>(); // Mapping string values to int keys hash_map.put(10, "Geeks"); hash_map.put(15, "4"); hash_map.put(20, "Geeks"); hash_map.put(25, "Welcomes"); hash_map.put(30, "You"); // Displaying the HashMap System.out.println("Initial Mappings are: " + hash_map); // Using keySet() to get the set view of keys System.out.println("The Collection is: " + hash_map.values()); } } Output: Initial Mappings are: {20=Geeks, 25=Welcomes, 10=Geeks, 30=You, 15=4} The Collection is: [Geeks, Welcomes, Geeks, You, 4] Program 2: Mapping Integer Values to String Keys.
Java // Java code to illustrate the values() method import java.util.*; import java.util.concurrent.*; public class ConcurrentHashMapDemo { public static void main(String[] args) { // Creating an empty ConcurrentHashMap ConcurrentHashMap<String, Integer> hash_map = new ConcurrentHashMap<String, Integer>(); // Mapping int values to string keys hash_map.put("Geeks", 10); hash_map.put("4", 15); hash_map.put("Geeks", 20); hash_map.put("Welcomes", 25); hash_map.put("You", 30); // Displaying the HashMap System.out.println("Initial Mappings are: " + hash_map); // Using keySet() to get the set view of keys System.out.println("The Collection is: " + hash_map.values()); } } Output: Initial Mappings are: {4=15, Geeks=20, You=30, Welcomes=25} The Collection is: [15, 20, 30, 25] Note: The same operation can be performed with any type of Mappings with variation and combination of different data types.
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