In this chapter, we will cover the following recipes:

• Using Symbol to create a local instance
• Using Symbol.for to create a global instance
• Using Symbol to simulate enums
• Setting and deleting entries from Map
• Creating a Map from the existing data
• Creating a class that wraps Map to work with specific complex types
• Setting and deleting entries from WeakMap
• Creating a WeakMap from existing data
• Creating a class that uses WeakMap to work with specific complex types