A **[hash table](https://www.educative.io/answers/what-is-a-hash-table)** is a collection of key-value pairs. The object to be used as a key should implement the `hashCode` and  `equals` methods and the key and the value should not be `null`. 
>You can read more about the difference between `HashTable` and `HashMap` [here](https://www.educative.io/answers/hashmap-vs-hashtable-in-java). 

#    
## What is the `clear()` method in `Hashtable`?

The **`clear()` method** of the `Hashtable` class removes all of the key and value entries from a specified `Hashtable` object. After calling this method, the `Hashtable` object becomes empty.

## Syntax

```java
public void clear()
```
This method doesn't take any parameters and does not return a value.

## Code

The code below shows how to use the `clear()` method.

import java.util.Hashtable;
class HashtableClearExample {
    public static void main( String args[] ) {
      
      Hashtable<Integer, String> numbers = new Hashtable<>();
      
      numbers.put(1, "one");
      numbers.put(2, "two");
      System.out.println("Hashtable is : "+ numbers);
      
      numbers.clear();
      
      System.out.println("\nAfter Calling Clear method");
      System.out.println("\nHashtable is : " + numbers);
    }
}

#   
## Explanation 

In the code above:

* In line 1, we import the `Hashtable` class.


* From lines 5 to 8, we create a `Hashtable` object and use the `put()` method to add two entries (`{1=one, 2=two}`) to the `numbers` object.

* In line 11, we use the `clear()` method to remove all the entries from the `numbers` object. This makes the `numbers` empty. 

* In line 14, we print `numbers` to ensure that it is empty. 

What is the Hashtable.clear method in Java?

The `clear()` method of Java's Hashtable class removes all entries, making it empty.

What is the Hashtable.clear method in Java?

What is the clear() method in Hashtable?

Syntax

Code

Explanation

What is the `clear()` method in `Hashtable`?