Typescript script to calculate factorial of a number

factorial.ts

// $ tsc factorial.ts && node factorial.js
// 3628800

function factorial(num: number) : number {
    if (num == 0) return 1
    else return num * factorial(num - 1)
}

console.log(factorial(10))

factorial(0) exceeds call stack.

factorial(0) exceeds call stack.

Right, added a condition to handle 0.