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Map interface summary Java.util interface map < K, V > Type parameter: K - indicates the key maintained by this mapping; V - indicates the corresponding value maintained by this mapping It is also called hash table and hash table. It is often used for data of key value pair structure. The key cannot be repeated, and the value can be ...

1 Map interface Map and Collection have no inheritance relationship The Map collection stores data in the form of key and value: key value pairs Both key and value are reference data types. Both key and value are memory addresses of storage objects. Key plays a leading role, and value is an accessory of key. Common methods in Map interf ...