# Proposal: 1) Number (integer or decimal) to Array 2) Array to Number (integer or decimal)

Jeremy Martin jmar777 at gmail.com
Thu Mar 7 22:11:57 UTC 2019

By "real world" we mean somewhere outside of a code challenge or similarly
low utility program context.

You mentioned statistics, for example. Can you reference a specific example
from that domain where these methods would offer an advantage?

On Thu, Mar 7, 2019, 5:05 PM guest271314 <guest271314 at gmail.com> wrote:

> Not sure what you mean by "real world" use case. Described at least one
> use case at the proposal. Statistics; graphs; number and integer
> manipulation using indexes of arrays with ability to convert manipulated
> array back to number.
>
> On Thu, Mar 7, 2019 at 9:56 PM Naveen Chawla <naveen.chwl at gmail.com>
> wrote:
>
>> What is the real world use case, presuming it's not just an academic
>> exercise
>>
>> On Thu, 7 Mar 2019, 9:08 pm guest271314, <guest271314 at gmail.com> wrote:
>>
>>> Ability to adjust *nth* digit of an integer or decimal by adjusting
>>> decimal or integer at *nth* index of array, to try to solve OEIS
>>> A217626 oeis.org/A217626 directly, for example
>>>     ~~(128.625*9*1.074)//1243
>>>     ~~(128.625*9*1.144)//1324
>>> where the decimal portion can be manipulated by referencing the index of
>>> an array, then converting the array back to a number.
>>>
>>> On Thu, Mar 7, 2019 at 8:55 PM Jeremy Martin <jmar777 at gmail.com> wrote:
>>>
>>>> Can you explain the motivation for this proposal?
>>>>
>>>> At first blush, this seems like an incredibly arbitrary pair of value
>>>> conversion utilities. Are there real world applications for this?
>>>>
>>>> On Thu, Mar 7, 2019 at 3:43 PM guest271314 <guest271314 at gmail.com>
>>>> wrote:
>>>>
>>>>>
>>>>>
>>>>> ---------- Forwarded message ---------
>>>>> From: guest271314 <guest271314 at gmail.com>
>>>>> Date: Thu, Mar 7, 2019 at 8:35 PM
>>>>> Subject: Proposal: 1) Number (integer or decimal) to Array 2) Array to
>>>>> Number (integer or decimal)
>>>>> To: <es-discuss at mozilla.org>
>>>>>
>>>>>
>>>>> Original concept: Integer or decimal to array and array to decimal or
>>>>> integer https://codegolf.meta.stackexchange.com/a/17223
>>>>>
>>>>> Proof of concept (with bugs)
>>>>>
>>>>> function numberToArray(n) {
>>>>>
>>>>>   if (Math.abs(n) == 0 || Math.abs(n) == -0) {
>>>>>     return [n]
>>>>>   }
>>>>>
>>>>>   const r = [];
>>>>>
>>>>>   let [
>>>>>     a, int = Number.isInteger(a), d = g = [], e = i = 0
>>>>>   ] = [ n || this.valueOf()];
>>>>>
>>>>>   if (!int) {
>>>>>     let e = ~~a;
>>>>>     d = a - e;
>>>>>     do {
>>>>>       if (d < 1) ++i;
>>>>>       d *= 10;
>>>>>     } while (!Number.isInteger(d));
>>>>>   }
>>>>>
>>>>>   for (; ~~a; r.unshift(~~(a % 10)), a /= 10);
>>>>>
>>>>>   if (!int) {
>>>>>     for (; ~~d; g.unshift(~~(d % 10)), d /= 10);
>>>>>     g[0] = g[0] * (1 * (10 ** -i))
>>>>>     r.push(...g);
>>>>>   }
>>>>>
>>>>>   return r;
>>>>> }
>>>>> function arrayToNumber(a) {