IdentityHashMap containsValue() Method in Java

The java.util.IdentityHashMap.containsValue() method is used to check whether a particular value is being mapped by a single or more than one key in the IdentityHashMap. It takes the Value as a parameter and returns True if that value is mapped by any of the keys in the map.

Syntax:

Identity_HashMap.containsValue(Object Value)

Parameters: The method takes just one parameter Value of Object type and refers to the value whose mapping is supposed to be checked by any key inside the map.

Return Value: The method returns boolean true if the mapping of the value is detected else false.

Below programs illustrate the java.util.IdentityHashMap.containsValue() Method:

Program 1: Mapping String Values to Integer Keys.

// Java code to illustrate the containsValue() method 
import java.util.*; 
  
public class Identity_Hash_Map_Demo { 
    public static void main(String[] args) 
    { 
  
        // Creating an empty IdentityHashMap 
        IdentityHashMap<Integer, String> identity_hash =  
                   new IdentityHashMap<Integer, String>(); 
  
        // Mapping string values to int keys 
        identity_hash.put(10, "Geeks"); 
        identity_hash.put(15, "4"); 
        identity_hash.put(20, "Geeks"); 
        identity_hash.put(25, "Welcomes"); 
        identity_hash.put(30, "You"); 
  
        // Displaying the IdentityHashMap 
        System.out.println("Initial Mappings are: " + 
                                          identity_hash); 
  
        // Checking for the Value 'Geeks' 
        System.out.println("Is the value 'Geeks' present? " +  
                        identity_hash.containsValue("Geeks")); 
  
        // Checking for the Value 'World' 
        System.out.println("Is the value 'World' present? " +  
                        identity_hash.containsValue("World")); 
    } 
} 

Output:

Initial Mappings are: {10=Geeks, 30=You, 20=Geeks, 25=Welcomes, 15=4}
Is the value 'Geeks' present? true
Is the value 'World' present? false

Program 2: Mapping Integer Values to String Keys.

// Java code to illustrate the containsValue() method 
import java.util.*; 
  
public class Identity_Hash_Map_Demo { 
    public static void main(String[] args) 
    { 
  
        // Creating an empty IdentityHashMap 
        IdentityHashMap<String, Integer> identity_hash =  
                      new IdentityHashMap<String, Integer>(); 
  
        // Mapping int values to string keys 
        identity_hash.put("Geeks", 10); 
        identity_hash.put("4", 15); 
        identity_hash.put("Geeks", 20); 
        identity_hash.put("Welcomes", 25); 
        identity_hash.put("You", 30); 
  
        // Displaying the IdentityHashMap 
        System.out.println("Initial Mappings are: " +  
                                             identity_hash); 
  
        // Checking for the Value '10' 
        System.out.println("Is the value '10' present? " +  
                           identity_hash.containsValue(10)); 
  
        // Checking for the Value '30' 
        System.out.println("Is the value '30' present? " +  
                           identity_hash.containsValue(30)); 
  
        // Checking for the Value '40' 
        System.out.println("Is the value '40' present? " +  
                          identity_hash.containsValue(40)); 
    } 
} 

Output:

Initial Mappings are: {Geeks=20, Welcomes=25, You=30, 4=15}
Is the value '10' present? false
Is the value '30' present? true
Is the value '40' present? false

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

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