Every possible sum of two digits

Every possible sum of two digitsCodewars

Approach

it's not finished. sorry I will write more cleary later

Solve the problem

1. split input each digit

2. iterate process-1 elements

   1. iterate and all 'n' + 1 th elements and sum process-2'th + process-2-1'th 'n'

Solution

JavaScript

const digits = (num) => [].concat(
  ...[...String(num)].map(Number)
    .map((v, i, arr) => {
        return arr.slice(i + 1).map((v2) => v + v2);
      }
    )
);