However, Java 2 re-engineered Hashtable so that it also implements the Map interface. I've created a test class Using the keys method. A Hashtable is an array of a list. It is similar to HashMap, but is synchronized. Like HashMap, Hashtable stores key/value pairs in a hash table. Thus, Hashtable is now integrated into the collections framework. How to iterate through Hashtable in Java? In this program, when the user enters a key the code should arrange to search the hashmap for the corresponding value and then print it. 1. Hashtable was part of the original java.util and is a concrete implementation of a Dictionary. How do you search for a key in a HashMap? This example also shows how to get all Hashtable keys using the keys method and keySet method. There are various ways in which we can iterate through hashtable keys, values, and entries as given below. How to iterate over Hashtable keys? The Overflow Blog Static site generation with single page app functionality? Java Hashtable class implements a hashtable, which maps keys to values. It is very much similar to HashMap in Java, with most significant difference that Hashtable is synchronized while HashMap is not.. How to get all keys of the Hashtable in Java? I'm trying to create a method which iterates through a hashtable and returns the key as a string, whats the best way to go about this? There are a couple of ways using which we can get all the keys of the hash table. Points to remember. HashTable forEach() method in Java with Examples Last Updated: 01-10-2019 The forEach(BiConsumer) method of Hashtable class perform the BiConsumer operation on each entry of hashtable until all entries have been processed or the action throws an exception. 1. It returns an enumeration of all keys contained in the hash table object. EDIT: copied from comment. Java Hashtable class contains unique elements. … We can get all the keys of the Hashtable using the keys method. Java Hashtable class is an implementation of hash table data structure. In this Hashtable tutorial, we will learn it’s internals, constructors, methods, use-cases and other important points.. Table of Contents 1. Each list is known as a bucket. It inherits Dictionary class and implements the Map interface. A Hashtable contains values based on the key. The position of the bucket is identified by calling the hashcode() method. java.util.Hashtable.get() Method - The get(Object key) method is used to get the value to which the specified key is mapped in this hashtable. Sorry if I didn't make it more clear, I'm trying to do this in Java. The Hashtable keys method returns an enumeration of all the keys contained in this hashtable object. Browse other questions tagged java algorithm data-structures linked-list hashtable or ask your own question.