IdentityHashMap get() Method in Java

Last Updated : 23 Jul, 2018

The java.util.IdentityHashMap.get() method of IdentityHashMap class is used to retrieve or fetch the value mapped by a particular key mentioned in the parameter. It returns NULL when the map contains no such mapping for the key.

Syntax:

IdentityHashMap.get(Object key_element)

Parameter: The method takes one parameter key_element of object type and refers to the key whose associated value is supposed to be fetched.

Return Value: The method returns the value associated with the key_element in the parameter.

Below programs illustrates the working of java.util.IdentityHashMap.get() method:

Program 1:

// Java code to illustrate the get() method 
import java.util.*; 
  
public class Identity_Hash_Map_Demo { 
    public static void main(String[] args) 
    { 
  
        // Creating an empty IdentityHashMap 
        Map<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); 
  
        // Getting the value of 25 
        System.out.println("The Value is: " +  
                                identity_hash.get(25)); 
  
        // Getting the value of 10 
        System.out.println("The Value is: " +  
                                identity_hash.get(10)); 
    } 
} 

Output:

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

Program 2:

// Java code to illustrate the get() method 
import java.util.*; 
  
public class Identity_Hash_Map_Demo { 
    public static void main(String[] args) 
    { 
  
        // Creating an empty IdentityHashMap 
        Map<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); 
  
        // Getting the value of "Geeks" 
        System.out.println("The Value is: " +  
                          identity_hash.get("Geeks")); 
  
        // Getting the value of "You" 
        System.out.println("The Value is: " +  
                            identity_hash.get("You")); 
    } 
} 

Output:

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

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

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