What are the reasons for excluding the Map interface from the Collection interface in programming language?

The Map interface in Java (and Android) does not inherit from the Collection interface because Map represents a data structure based on key-value pairs, whereas Collection is a set of elements without keys.

Main reasons:

• Semantic difference: Collection describes groups of elements that can be iterated over, while Map is a mapping of keys to values.
• Different operations: Collection methods are focused on working with elements, while Map methods are focused on working with pairs (key, value).
• Avoiding API conflicts: If Map inherited from Collection, it would be necessary to decide how to interpret keys and values as collection elements.

Thus, Map and Collection are different interfaces with different contracts, reflecting their different concepts in the language.