How would I make a factorial calculator function?

Ask coding questions

How would I make a factorial calculator function?

How would I make a factorial calculator function? I need that to make a permutations and combinations calculator. I am pretty sure you would need a loop of some sort, but I'm not sure how to do it. Thanks for the help!

Voters

Chiragchachada

CodyChoo

RohilPatel

Comments

hot new top

[deleted]

have you tried googling? I found this quite easily: https://www.sitesbay.com/javascript/javascript-factorial-of-number
Do you know about recursion? It can be used instead of a loop: https://www.w3resource.com/javascript-exercises/javascript-recursion-function-exercise-1.php

RohilPatel

Sort of but not much luck , @malvoliothegood

mwilki7

factorials: n × (n - 1) × (n - 2) ... 2 × 1

you can try using for loop variable to start at n and go to 1
and get something to hold the product of the multiplication inside the loop

RohilPatel

Wdym? @mwilki7

mwilki7

@RohilPatel
this is how you can implement the factorial function on your calculator

RohilPatel

How do get the number of numbers before hitting 1? @mwilki7


let product = 1;
for (let i = 0; i < n; i++)
{
    product *= i;
}

RohilPatel

Is n the number ur "factorialing" by? @mwilki7

mwilki7

@RohilPatel
yes, if i want to find the factorial of 5, n would be 5

RohilPatel

Hmm, it's not working. @mwilki7

mwilki7

@RohilPatel
what are the results you are getting

RohilPatel

Try it ur self. @mwilki7

SixBeeps

@RohilPatel Make the iterator start from 1 and not 0. Multiplication by 0 just makes the product, well, 0.

mwilki7

@SixBeeps
shoot how did i miss that

SixBeeps

@mwilki7 Don't worry, I spent all morning today wondering why my webpage wasn't running. Turns out I spelled "replace" as "replase" :/