How to use a Hash Table in TypeScript

A Hash Table is a data structure that stores data in an associative array format, where each data element is assigned a unique key. The key is then used to access the data in constant time, making it a very efficient data structure for searching, inserting, and deleting data. The Hash Table uses a hash function to map the key to an index in an array, where the data is stored. The hash function ensures that each key is mapped to a unique index, and collisions are handled by using a collision resolution technique such as chaining or open addressing. The Hash Table is widely used in computer science applications such as databases, compilers, and network routers. Keep reading below to learn how to use a Hash Table in TypeScript.

How to use a Hash Table in TypeScript with example code

Hash tables are a fundamental data structure in computer science that allow for efficient storage and retrieval of key-value pairs. In TypeScript, hash tables are implemented using the built-in `Map` class.

To create a new hash table, simply instantiate a new `Map` object:


const myMap = new Map();


To add a new key-value pair to the hash table, use the `set` method:


myMap.set('key', 'value');


To retrieve a value from the hash table, use the `get` method:


const value = myMap.get('key');


To check if a key exists in the hash table, use the `has` method:


if (myMap.has('key')) {
// do something
}


To remove a key-value pair from the hash table, use the `delete` method:


myMap.delete('key');


It’s important to note that keys in a hash table must be unique. If you try to add a key that already exists, the previous value will be overwritten.

Hash tables are incredibly useful for a wide range of applications, from caching to indexing. By using the built-in `Map` class in TypeScript, you can easily implement hash tables in your own projects.

What is a Hash Table in TypeScript?

In conclusion, a Hash Table is a powerful data structure that allows for efficient storage and retrieval of key-value pairs. In TypeScript, Hash Tables can be implemented using built-in Map and Set objects, or by creating custom classes that use hashing algorithms to map keys to indices in an array. By using Hash Tables, developers can optimize their code for faster performance and more efficient memory usage. Whether you’re working on a small project or a large-scale application, understanding how to use Hash Tables in TypeScript can help you write more efficient and effective code.