The java.util.LinkedHashMap.clear() is an inbuilt method of LinkedHashMap class in Java and is used to clear all the elements or the mappings from the denoted LinkedHashMap. The map will become empty after the operation is performed.
Syntax:
Linked_Hash_Map.clear()
Parameters: The method does not take any parameters.
Return Value: The method does not return any value.
Below programs illustrate the java.util.LinkedHashMap.clear() method:
Program 1: Mapping String Values to Integer Keys.
// Java code to illustrate the clear() methodimport java.util.*;  public class Linked_Hash_Map_Demo {    public static void main(String[] args)    {        // Creating an empty LinkedHashMap        LinkedHashMap<Integer, String> li_hash_map =        new LinkedHashMap<Integer, String>();          // Mapping string values to int keys        li_hash_map.put(10, "Geeks");        li_hash_map.put(15, "4");        li_hash_map.put(20, "Geeks");        li_hash_map.put(25, "Welcomes");        li_hash_map.put(30, "You");          // Displaying the LinkedHashMap        System.out.println("Initial Mappings are: " + li_hash_map);          // Clearing the linked hash map using clear()        li_hash_map.clear();          // Displaying the final HashMap        System.out.println("Finally the maps look like this: " + li_hash_map);    }} |
Output:
Initial Mappings are: {10=Geeks, 15=4, 20=Geeks, 25=Welcomes, 30=You}
Finally the maps look like this: {}
Program 2: Mapping Integer Values to String Keys.
// Java code to illustrate the clear() methodimport java.util.*;  public class Linked_Hash_Map_Demo {    public static void main(String[] args)    {          // Creating an empty LinkedHashMap        LinkedHashMap<String, Integer> li_hash_map =        new LinkedHashMap<String, Integer>();          // Mapping int values to string keys        li_hash_map.put("Geeks", 10);        li_hash_map.put("4", 15);        li_hash_map.put("Geeks", 20);        li_hash_map.put("Welcomes", 25);        li_hash_map.put("You", 30);          // Displaying the LinkedHashMap        System.out.println("Initial Mappings are: " + li_hash_map);          // Clearing the linked hash map using clear()        li_hash_map.clear();          // Displaying the final HashMap        System.out.println("Finally the maps look like this: " + li_hash_map);    }} |
Output:
Initial Mappings are: {Geeks=20, 4=15, Welcomes=25, You=30}
Finally the maps look like this: {}
Note: The same operation can be performed with any type of Mappings with variation and combination of different data types.
