For the Java Collection understanding

First, the three main interfaces of the set frame

Collection: Root interface of all classes map: Map interface, store key value pair Iterator: Iterate interface for iterating over set

Collection Sub-interfaces:

List: An orderly interface, an orderly deposit of elements

List common Interface Implementation classes: ArrayList, LinkedList, Vector

　　　　　　

Set: No duplicate collection, that is, the set element that is deposited is not duplicated

Map interface: The map interface holds the key value pairs namely: Map<key,value>, where the key value is not allowed to repeat, if there are duplicates, then

Put (k key, V value), save the value of key with a map

Get (object k), which returns the value of value according to the values of K

Size (), returns the number of key-value teams

Implementation classes for MAP interfaces: HashMap, TreeMap

　　　　　　

For the Java Collection understanding