The java.util.WeakHashMap.entrySet() method in Java is used to create a set out of the same elements contained in the map. It basically returns a set view of the weak hash map or we can create a new set and store the map elements into them.
Syntax:
weak_hash_map.entrySet()
Parameters: The method does not take any parameter.
Return Value: The method returns a set having same elements as the map.
Below programs illustrate the java.util.WeakHashMap.entrySet() Method:
Program 1: Mapping String Values to Integer Keys.
// Java code to illustrate the entrySet() methodimport 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 entrySet() to get the set view        System.out.println("The set is: " + weak_hash.entrySet());    }} |
Output:
Initial Mappings are: {30=You, 15=4, 10=Geeks, 25=Welcomes, 20=Geeks}
The set is: [30=You, 15=4, 10=Geeks, 25=Welcomes, 20=Geeks]
Program 2: Mapping Integer Values to String Keys.
// Java code to illustrate the entrySet() methodimport 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 entrySet() to get the set view        System.out.println("The set is: " + weak_hash.entrySet());    }} |
Output:
Initial Mappings are: {Welcomes=25, 4=15, You=30, Geeks=20}
The set is: [Welcomes=25, 4=15, You=30, Geeks=20]
Note: The same operation can be performed with any type of Mappings with variation and combination of different data types.
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