Today, we're diving into maps in TypeScript. A map in TypeScript stores data as key-value pairs, emphasizing type safety by allowing you to define specific types for keys and values. We'll explore how to create maps with type annotations and delve into the intricacies of their performance.

Maps in TypeScript are versatile data structures. They store key-value pairs and allow you to set defined types for each, ensuring type safety throughout your codebase.

Here is how we create an empty map with specific types for keys and values:

TypeScript
Copy to clipboard
1let myMap: Map<string, number> = new Map(); // creates an empty Map with string keys and number values

In the code above, myMap is a new TypeScript map, specifically defined to accept string keys and number values, ensuring robust and error-free storage.

Maps in TypeScript come equipped with essential methods:

• set(key, value): Stores a key-value pair.
• get(key): Retrieves the value associated with a key.
• has(key): Checks if a key exists and returns true or false.
• delete(key): Removes a key-value pair.
• size: Returns the count of key-value pairs.

To better understand these methods, let's apply them:

TypeScript
Copy to clipboard
1let myMap: Map<string, number> = new Map();
2
3// Add pairs with set
4myMap.set('apples', 10); // Adds a new pair
5myMap.set('bananas', 6); // Adds another pair
6
7// Use get
8console.log(myMap.get('apples')); // Outputs: 10, retrieves the value for 'apples'
9
10// Apply has
11console.log(myMap.has('bananas')); // Outputs: true, checks for the existence of 'bananas'
12
13// Delete with delete
14myMap.delete('bananas'); // Removes 'bananas' and its value from the map
15
16// Check size
17console.log(myMap.size); // Outputs: 1, gives the number of pairs

The time complexity for operations such as get, set, has, and delete in maps is $O(1)$. This means they execute very quickly, regardless of the map's size.

Imagine managing a warehouse with thousands of products. A map allows you to efficiently manage any product in no time!

Excellent work! You've now learned about TypeScript maps. Use what you've learned to enhance your practice exercises. Keep exploring the possibilities with maps in a TypeScript context, and remain curious!