How to use Recursive Types with Generics In Typescript

Q: How to use Recursive Types with Generics In Typescript

Type aliases can also be recursive in TypeScript. This allows for more flexible and complex type definitions compared to interfaces, as type aliases can involve unions, intersections, and other complex types.

Recursive Type Aliases

Recursive Types for Function Definitions

Recursive types and interfaces become even more powerful when combined with generics, enabling the definition of complex, self-referential structures that can contain various types of data.

Syntax:

interface RecursiveGenericInterface<T> {
  value: T;
  next?: RecursiveGenericInterface<T>;
}

Example: To demonstrate creating a linked list of numbers by using generic interface which allows for the creation of linked list nodes that can hold any type of data.

Javascript

interface GenericListNode<T> {
  value: T;
  next?: GenericListNode<T>;
}
 
const node1: GenericListNode<number> = 
    { value: 123 };
const node2: GenericListNode<number> = 
    { value: 456, next: node1 };
 
console.log(node2);

Output

[LOG]: {   "value": 456,   "next": {     "value": 123   } }

What are Recursive Types & Interfaces in TypeScript ?

In TypeScript, recursive types and interfaces are used to define types or interfaces that can refer to themselves in their definition. This is a powerful concept that allows you to describe complex, nested structures with a simple, elegant definition.