split_string_in_pieces_with_reduce.js

const split = (str, nmb) => {
    return str.split('')
        .reduce((arr, rec) => {
            console.log(`Arr: ${arr} Rec : ${rec}`)
            if (arr[arr.length - 1].length < nmb) {
                arr[arr.length - 1] = [...arr[arr.length - 1], rec]
                return arr
            }
            return [...arr, [rec]]
        }, [[]])
        .map(el => el.join(''))
}