The implementation details of the Java collection of the programmer's basic skills

1.Set Collections and Maps

Careful comparison of the above set and map under the interface name, it is not difficult to find that they are so similar, there must be a reason

If you only look at the map key will find that they can not be repeated, there is no order, that is, the map of all the key together is a set set, so map has a method set<k> keySet ();

For a map, in fact, he's the equivalent of a set set of all the elements that are key-value.

Question: How to implement a map with set??

Idea: Define a Simpleentry class that represents a Key-value pair, which can be used as a map when the elements in the set set are Simpleentry, so that the set

Not to be continued ....

The implementation details of the Java collection of the programmer's basic skills