Can you give examples of where hash table data structure is used?

Hash tables are widely used for fast data access by key. Examples of use:

• Implementation of dictionaries and associative arrays (e.g., dict in Python).
• Caching data to speed up repeated requests.
• Indexing databases for quick search.
• Counting the frequency of element occurrence (e.g., words in a text).
• Implementing sets (set) for fast search and deletion of elements.

Example in Python:

# Counting the number of words in a list
words = ['apple', 'banana', 'apple', 'orange', 'banana', 'apple']
count = {}
for word in words:
    count[word] = count.get(word, 0) + 1
print(count)  # {'apple': 3, 'banana': 2, 'orange': 1}