Today, we're learning about Map
in JavaScript. A Map stores data as key-value pairs. We'll recall how to create Maps, implement them, and delve into the details of their memory management.
Maps are versatile data structures in JavaScript. They store key-value pairs and accept any data type as a key — even objects and functions!
Here is how we create an empty Map:
Here, myMap
is a new JavaScript Map, eagerly awaiting to store your keys and values.
Maps provide some essential built-in methods:
set(key, value)
: Stores a key-value pair.get(key)
: Retrieves the value of a key.has(key)
: Checks if a key exists and returnstrue
orfalse
.delete(key)
: Erases a key-value pair.size
: Returns the count of key-value pairs.
To gain a better understanding, let's apply these methods:
JavaScript uses a Hash Table to implement Maps. This table ensures the Map's size adjusts based on the stored data, optimizing memory usage.
The time complexity of get
, set
, has
, and delete
operations in Maps is O(1)
. This signifies that they execute instantly, regardless of the Map's size.
Imagine running a store with thousands of items. A Map lets you quickly handle any item!
Excellent work! You've now learned about JavaScript Maps. Use what you've learned in your practice exercises. Keep exploring Maps and stay curious!
