Welcome to our JavaScript data structures revision! Today, we will delve deeply into JavaScript Maps. Much like a bookshelf, Maps allow you to quickly select the book (value) you desire by reading its label (key). They are vital to JavaScript for quickly accessing values using keys and for efficient key insertion and deletion. So, let's explore JavaScript Maps for a clearer understanding of these concepts.

Our journey starts with JavaScript Maps, a pivotal data structure that holds data as key-value pairs. Imagine storing your friend's contact info in such a way that allows you to search for your friend's name (the key) and instantly find their phone number (the value).

In the above code, we create a PhoneBook class that uses a Map to store contacts. As you can see, Maps simplify the processes of adding, modifying, and accessing information with unique keys.

JavaScript Maps enable a variety of operations for manipulating data, such as setting, getting, deleting key-value pairs, and more. Understanding these operations is crucial for efficient data handling in JavaScript.

To add or update entries in a Map, you use the method. If the key exists, the value is updated; if not, a new key-value pair is added. This flexibility allows for dynamic updates and additions to the Map without needing a predefined structure.