Java: Get a shallow copy of a HashMap instance

Last update on May 22 2025 13:15:29 (UTC/GMT +8 hours)

6. Get Shallow Copy of HashMap

Write a Java program to get a shallow copy of a HashMap instance.

Sample Solution:-

Java Code:

import java.util.*;  
public class Example6 {  
   public static void main(String args[]){  
  HashMap<Integer,String> hash_map= new HashMap<Integer,String>();  
  hash_map.put(1, "Red");
  hash_map.put(2, "Green");
  hash_map.put(3, "Black");
  hash_map.put(4, "White");
  hash_map.put(5, "Blue");
    // print the map
   System.out.println("The Original map: " + hash_map);
   HashMap<Integer,String> new_hash_map= new HashMap<Integer,String>(); 
   new_hash_map = (HashMap)hash_map.clone();     
   System.out.println("Cloned map: " + new_hash_map);        
     }
}

Sample Output:

Note: Example6.java uses unchecked or unsafe operations.               
Note: Recompile with -Xlint:unchecked for details.                     
The Original map: {1=Red, 2=Green, 3=Black, 4=White, 5=Blue}           
Cloned map: {1=Red, 2=Green, 3=Black, 4=White, 5=Blue}

For more Practice: Solve these Related Problems:

Write a Java program to clone a HashMap using the clone() method and then modify the clone without affecting the original.
Write a Java program to create a shallow copy of a map using its copy constructor and verify that both maps have identical key-value pairs.
Write a Java program to copy a map into a new map using Java streams and collect() and then print the new map.
Write a Java program to perform a shallow copy of a map and then demonstrate that modifying the objects in the copy affects the original map.

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Java Code Editor:

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