left pad string (pad start), isArray, isPositiveInt

utilities.js

function leftPad(str, padLength) {
    const arr = str.split(" ")
    Array.from(Array(padLength).keys()).forEach(x => arr.push(" "))
    return arr.reverse().join().replace(/,/g, '')
}

const isArray = (x) => x.hasOwnProperty('length');

const isPositiveInt = (n) => n > 0;