Java — Which interface does java.util.Hashtable implement?

Introduction / Context:
The java.util.Hashtable class is one of the legacy collection classes in Java. Understanding which interfaces it implements is key to using it correctly in modern Java programming.

Given Data / Assumptions:

• Hashtable is a dictionary-like data structure storing key-value pairs.
• Located in java.util package.
• Modern usage often prefers HashMap, but Hashtable remains important historically.

Concept / Approach:
Hashtable implements the Map interface, which defines methods for mapping keys to values without duplicates.

Step-by-Step Reasoning:

Why Other Options Are Wrong:

• List → ordered sequence, not key-value mapping.
• HashTable (spelled incorrectly) is not an interface.
• Collection is more general, but Hashtable implements Map, not Collection directly.

Final Answer:
java.util.Map