HashMap values() Method in Java

Posted on by fluxmeister0

The java.util.HashMap.values() method of HashMap 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 HashMap.

Syntax:

Hash_Map.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 java.util.HashMap.values() Method:
Program 1: Mapping String Values to Integer Keys.

// Java code to illustrate the values() method 
import java.util.*; 

public class Hash_Map_Demo { 
	public static void main(String[] args) 
	{ 

		// Creating an empty HashMap 
		HashMap<Integer, String> hash_map = new HashMap<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 values() to get the set view of values 
		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.filter_none

// Java code to illustrate the values() method 
import java.util.*; 

public class Hash_Map_Demo { 
	public static void main(String[] args) 
	{ 

		// Creating an empty HashMap 
		HashMap<String, Integer> hash_map = new HashMap<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 values() to get the set view of values 
		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.

 

Recommended Posts:

Source: link