Java HashMap clone() Method
Example
Create a copy of a map and change it:
import java.util.HashMap;
public class Main {
public static void main(String[] args) {
HashMap<String, String> capitalCities = new HashMap<String, String>();
capitalCities.put("England", "London");
capitalCities.put("Germany", "Berlin");
capitalCities.put("Norway", "Oslo");
capitalCities.put("USA", "Washington DC");
HashMap copy = (HashMap)capitalCities.clone();
copy.remove("England");
System.out.println(capitalCities);
System.out.println(copy);
}
}
Definition and Usage
The clone()
method returns a copy of the map as an Object
.
This creates a "shallow" copy, which means that copies of objects in the map are not created, instead the map has references to the same objects that are in the original map.
Note: Since the return type is Object
, it must be type casted in order to use it as a HashMap
as shown in the example above.
Syntax
public Object clone()
Technical Details
Returns: | A copy of the HashMap object. |
---|
Related Pages
❮ HashMap Methods