IdentityHashMap clone() Method in Java

Last Updated : 23 Jul, 2018

The java.util.IdentityHashMap.clone() method is used to return a shallow copy of the mentioned hash map. It just creates a copy of the map.

Syntax:

Identity_HashMap.clone()

Parameters: The method does not take any parameters.

Return Value: The method just returns a copy of the hash map.

Below programs are used to illustrate the working of java.util.IdentityHashMap.clone() Method:
Program 1:

// Java code to illustrate the clone() 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);
  
        // Displaying the cloned Map using clone()
        System.out.println("The cloned map: " + 
                                    identity_hash.clone());
    }
}

Output:

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

Program 2:

// Java code to illustrate the clone() method
import java.util.*;
  
public class Identity_Hash_Map_Demo {
    public static void main(String[] args)
    {
  
        // Creating an empty hash map
        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);
  
        // Displaying the cloned map using clone()
        System.out.println("The cloned map: " + 
                                 identity_hash.clone());
    }
}

Output:

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

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

Attention reader! Don’t stop learning now. Get hold of all the important Java Foundation and Collections concepts with the Fundamentals of Java and Java Collections Course at a student-friendly price and become industry ready. To complete your preparation from learning a language to DS Algo and many more, please refer Complete Interview Preparation Course.

My Personal Notes

Related Articles

IdentityHashMap clone() Method in Java