What are the advantages of using a hash table compared to a regular array for storing data?

A hash table (for example, a dictionary in Python) has several advantages over a regular array when storing data:

• Fast key-based access — search, insert, and delete operations are performed on average in O(1), whereas in an array, search by value requires O(n).
• Flexibility of keys — the key can be not only an index but also a string, tuple, or another hashable object.
• No need to know the size in advance — the hash table dynamically expands.

Example of using a dictionary in Python:

phone_book = {
    'Ivan': '+71234567890',
    'Maria': '+79876543210'
}

print(phone_book['Ivan'])  # Fast access by key