JavaScript中是否有用于找到数字阶乘的内置方法？

Question

Are there any build-in methods for finding the factorial of a number which we can use in place of reusable functions like the example below:

 function factorial(x) { for (let i = x - 1; i >= 1; i--) { x= x * i; } return x; } alert(factorial(16)); 

Answer 1

不可以， Math对象确实不提供这种方法。

Answer 2

There is no in-build factorial function. However, as a side note, you can simplify your function as following

 function factorial(x) { return (x > 1) ? x * factorial(x-1) : 1; } console.log(factorial(5)); 

Answer 3

There are no built-in functions to do the factorial of a number in JavaScript, but you could make a .js file just for this purpose, and import it in each file you intend to use it for.
Take a look at this question: How do I include a JavaScript file in another JavaScript file? for importing files. I believe this is the closest you can get for what you want.

As Nikos already mentioned in a comment, you should beware overflowing for large factorial numbers, as the highest number you can get to is 2^53 - 1 for integers, or 2^32-1 for bitwise operations. Make your own BigInt library, or search for one: there exist many open-source ones out there.