Learning TypeScript 2.x - Second Edition

Recursion

A function that calls itself is known as a recursive function. The following function is a recursive function that allows us to calculate the factorial of a given number n. The factorial is the product of all positive integers less than or equal to n:

const factorial = (n: number): number => 
(n === 0) ? 1 : (n * factorial(n - 1)); 

We can invoke the preceding function as follows:

factorial(5); // 120