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Java HashMap clone() Method with Example

HashMap Class clone() method: Here, we are going to learn about the clone() method of HashMap Class with its syntax and example.
Submitted by Preeti Jain, on March 04, 2020

HashMap Class clone() method

• clone() method is available in java.util package.
• clone() method is used to get a cloned copy of this HashMap instance or in other words, we can say it returns a shallow copy of this HashMap.
• clone() method is a non-static method, it is accessible with the class object only and if we try to access the method with the class name then we will get an error.
• clone() method does not throw an exception at the time of cloning an object.

Syntax:

    public Object clone();

Parameter(s):

• It does not accept any parameter.

Return value:

The return type of the method is Object, it clones this HashMap.

Example:

// Java program to demonstrate the example 
// of Object clone() method of HashMap 

import java.util.*;

public class CloneOfHashMap {
    public static void main(String[] args) {
        // Instantiates a HashMap object
        HashMap < Integer, String > hm = new HashMap < Integer, String > ();
        HashMap < Integer, String > clone_map = new HashMap < Integer, String > ();

        // By using put() method is to add
        // key-value pairs in a TreeMap
        hm.put(10, "C");
        hm.put(20, "C++");
        hm.put(50, "JAVA");
        hm.put(40, "PHP");
        hm.put(30, "SFDC");

        // Display HashMap and clone_map
        System.out.println("HashMap: " + hm);
        System.out.println("CloneMap: " + clone_map);

        // By using clone() method is to clone
        // this object
        clone_map = (HashMap) hm.clone();

        //Display clone_map
        System.out.println("hm.clone(): " + clone_map);
    }
}

Output

HashMap: {50=JAVA, 20=C++, 40=PHP, 10=C, 30=SFDC}
CloneMap: {}
hm.clone(): {40=PHP, 50=JAVA, 10=C, 20=C++, 30=SFDC}