A LinkedHashMap
is the same as a HashMap
, except that a LinkedHashMap
maintains the insertion order, whereas a HashMap
doesn’t. Internally, the LinkedHashMap
uses a doubly-linked list to maintain the insertion order.
remove
methodIn LinkedHashMap
, we can use the remove
method to remove the mapping of the specified key.
public V remove(Object key)
The key
whose mapping is to be removed is passed as an argument.
If there is a mapping present for the specified key, then the mapping is removed and the removed value is returned.
If there is no mapping present for the specified key, then null
is returned.
The below example shows how to use the remove
method.
import java.util.LinkedHashMap;class RemoveExample {public static void main( String args[] ) {LinkedHashMap<Integer, String> map = new LinkedHashMap<>();map.put(1, "one");map.put(2, "two");System.out.println("The map is -" + map );String returnValue = map.remove(1);System.out.println("\nThe return value for remove method is -" + returnValue);System.out.println("The map is -" + map );returnValue = map.remove(3);System.out.println("\nThe return value for remove method is -" + returnValue);System.out.println("The map is -" + map );}}
In the code above:
In line 1, we imported the LinkedHashMap
class.
In line 5, we created a LinkedHashMap
object with the name map
.
In lines 6 and 7, we used the put
method to add two mappings ({1=one, 2=two}
) to the map
object.
In line 10, we used the remove
method to remove the mapping for the key 1
.
In line 14, we used the remove
method to remove the mapping for the key 3
. There is no such entry present, so null
will be returned.