One, set usage
set converts an array
Adding duplicate elements doesn't work
(Application: Deduplication function) The conversion process will not have data type conversion
Add, delete, determine whether there is a method
2.
Several methods of reading (traversing)
二、WeakSet
The difference with Set:
1. The elements of WeakSet can only be objects
2. The object of WeakSet is a weak application (it will not detect whether it has been used in other applications, and is not linked to the recycling mechanism)
3. Cannot be traversed, some properties and methods of Set are not available
1.
can only be objects
3. Map
1. The method of generating a Map object
1.
2.
2. Common property values and methods
(Map traversal is the same as Set method)
4. WeakMap
The difference between WeakMap and Map is the same as the difference between WeakSet and Set
