The java.util.Hashtable.clear() method in Java is used to clear and remove all of the keys from a specified Hashtable.
Syntax:
Hash_table.clear()
Parameters: The method does not accept any parameters.
Return Value: The method does not return any value. Below programs are used to illustrate the working of java.util.Hashtable.clear() Method:
Program 1:
Java
// Java code to illustrate the clear() methodimport java.util.*;public class Hash_Table_Demo { public static void main(String[] args) { // Creating an empty Hashtable Hashtable<Integer, String> hash_table = new Hashtable<Integer, String>(); // Inserting Values into table hash_table.put(10, "Geeks"); hash_table.put(15, "4"); hash_table.put(20, "Geeks"); hash_table.put(25, "Welcomes"); hash_table.put(30, "You"); // Displaying the Hashtable System.out.println("The Hashtable is: " + hash_table); // Clearing the hash table using clear() hash_table.clear(); // Displaying the final Hashtable System.out.println("Finally the table looks like this: " + hash_table); }} |
Output:
The Hashtable is: {10=Geeks, 20=Geeks, 30=You, 15=4, 25=Welcomes}
Finally the table looks like this: {}
Program 2:
Java
// Java code to illustrate the clear() methodimport java.util.*;public class Hash_Table_Demo { public static void main(String[] args) { // Creating an empty Hashtable Hashtable<String, Integer> hash_table = new Hashtable<String, Integer>(); // Inserting Values into table hash_table.put("Geeks", 10); hash_table.put("4", 15); hash_table.put("Geeks", 20); hash_table.put("Welcomes", 25); hash_table.put("You", 30); // Displaying the Hashtable System.out.println("The Hashtable is: " + hash_table); // Clearing the hash table using clear() hash_table.clear(); // Displaying the final Hashtable System.out.println("Finally the table looks like this: " + hash_table); }} |
Output:
The Hashtable is: {You=30, Welcomes=25, 4=15, Geeks=20}
Finally the table looks like this: {}
Note: The same operation can be performed with any type of variation and combination of different data types.
