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 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 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.
