How to convert an integer into an array of digits

Question

I want to convert an integer, say 12345, to an array like [1,2,3,4,5].

I have tried the below code, but is there a better way to do this?

Answer 1

You can just use the String() method. It coverts to string but you can use them in term of digits.

let numbers = String(val);
console.log(numbers);

Answer 2

First, the integer is converted string & then to array. Using map function, individual strings are converted to numbers with the help of parseInt function. Finally, that array is returned as the result.

const digitize = n => [...`${n}`].map(i => parseInt(i));

Answer 3

Here are the two methods I usually use for this. The first method:

function toArr1(n) {
    "use strict";
    var sum = 0;    
    n = Array.from(String(n), Number); 
       /*even if the type of (n) was a number it will be treated as a string and will 
    convert to an Array*/
    for (i = 0; i < n.length; i += 1) {
        sum += n[i];
    }
    return sum;
}

The second method:

function toArr2(n) {
    var sum = 0;
    n = n.toString().split('').map(Number);
    for (i = 0; i < n.length; i += 1) {
        sum += n[i]; 
    }
    return sum;
}

Answer 4

Another way is by using literals and then spread:

const n = 12345;
const arr = [...`${n}`].map(Number);
console.log(arr);

Answer 5

The solutions proposed work fine in most cases but not with negative numbers.

There is a solution for such cases.

const intToArray = (int) => {
  return String(int).match(/-?\d/g).map(Number)
}

console.log(intToArray(312)) // [3, 1, 2]
console.log(intToArray(-312)) // [-3, 1, 2]