WeakHashMap values() Method in Java

The java.util.WeakHashMap.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 Map.

Syntax:

Weak_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.WeakHashMap.values() Method:
Program 1:

// Java code to illustrate the values() method 
import java.util.*; 
  
public class Weak_Hash_Map_Demo { 
    public static void main(String[] args) 
    { 
  
        // Creating an empty WeakHashMap 
        Map<Integer, String> weak_hash = new 
                     WeakHashMap<Integer, String>(); 
  
        // Mapping string values to int keys 
        weak_hash.put(10, "Geeks"); 
        weak_hash.put(15, "4"); 
        weak_hash.put(20, "Geeks"); 
        weak_hash.put(25, "Welcomes"); 
        weak_hash.put(30, "You"); 
  
        // Displaying the WeakHashMap 
        System.out.println("Initial Mappings are: " +  
                                          weak_hash); 
  
        // Using values() to get the set view of values 
        System.out.println("The collection is: " +  
                                   weak_hash.values()); 
    } 
} 

Output:

Initial Mappings are: {30=You, 15=4, 10=Geeks, 25=Welcomes, 20=Geeks}
The collection is: [You, 4, Geeks, Welcomes, Geeks]

Program 2:

// Java code to illustrate the values() method 
import java.util.*; 
  
public class Weak_Hash_Map_Demo { 
    public static void main(String[] args) 
    { 
  
        // Creating an empty WeakHashMap 
        Map<String, Integer> weak_hash = new 
                     WeakHashMap<String, Integer>(); 
  
        // Mapping int values to string keys 
        weak_hash.put("Geeks", 10); 
        weak_hash.put("4", 15); 
        weak_hash.put("Geeks", 20); 
        weak_hash.put("Welcomes", 25); 
        weak_hash.put("You", 30); 
  
        // Displaying the WeakHashMap 
        System.out.println("Initial Mappings are: " +  
                                          weak_hash); 
  
        // Using values() to get the set view of values 
        System.out.println("The collection is: " +  
                                   weak_hash.values()); 
    } 
} 

Output:

Initial Mappings are: {Welcomes=25, 4=15, You=30, Geeks=20}
The collection is: [25, 15, 30, 20]

Note: The same operation can be performed with any type of Mappings with variation and combination of different data types.

Don’t stop now and take your learning to the next level. Learn all the important concepts of Data Structures and Algorithms with the help of the most trusted course: DSA Self Paced. Become industry ready at a student-friendly price.

My Personal Notes

Recommended Posts: