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() methodimport 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")); }} |
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() methodimport 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)); }} |
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.
