NodeJs: Hashmap Operations

Hash maps are useful in Node.js when you need to store and retrieve key-value pairs quickly and efficiently.

The primary advantage of using a hash map over other data structures like arrays or linked lists is that hash maps offer constant time complexity (O(1)) for adding, retrieving, and deleting elements, regardless of the size of the map. This makes hash maps ideal for applications where fast access to data is critical.

In JavaScript, you can create a hash map using an object literal or the Map class. Both data structures are used for mapping key-value pairs, but they have some differences in how they work and the features they provide.

Here’s an example of creating a hash map using an object literal:

const hashMap = {
  key1: 'value1',
  key2: 'value2',
  key3: 'value3',
};

In the example above, the hashMap variable is an object literal with three key-value pairs.

Here’s an example of creating a hash map using the Map class:

const hashMap = new Map();
hashMap.set('key1', 'value1');
hashMap.set('key2', 'value2');
hashMap.set('key3', 'value3');

In the example above, the hashMap variable is a Map instance with three key-value pairs. The set() method is used to add key-value pairs to the map.