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Kuidas on organiseeritud kogude struktuur ja kuidas nad on omavahel seotud?
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In Android (and generally in Java), collections are organized in a hierarchy of interfaces and classes that provide storage and management of groups of objects.
Main interfaces of collections:
- Collection — the base interface for all collections.
- List — an ordered list of elements with access by index (e.g., ArrayList, LinkedList).
- Set — a collection of unique elements (e.g., HashSet, TreeSet).
- Queue — a collection for storing elements in processing order (e.g., LinkedList, PriorityQueue).
Additionally, there is the Map interface, which does not inherit from Collection but is related to collections — it stores key-value pairs (e.g., HashMap, TreeMap).
Relationship between them:
- List, Set, and Queue extend Collection.
- Map is a separate structure for key-value pairs.
Example: ArrayList implements List, which extends Collection, so ArrayList can be used as both a Collection and a List.
This structure allows choosing the appropriate collection depending on requirements for uniqueness, order, and access method to elements.