In which cases is it advisable to use a HashMap data structure?

HashMap (in Python, the equivalent is a dict) is useful when you need to efficiently store and quickly retrieve data by key. Main use cases:

• Fast access to elements by a unique key (average O(1))
• When the order of elements does not matter
• For implementing caching, indexing, frequency counting

Example of using a dictionary in Python:

users = {"alice": 25, "bob": 30}
age = users.get("alice")  # quickly get the age