Code Challenge: 2018-01-30 - https://repl.it/@itzjonas/StarTower

StarTowerNew.js

const starTowerNew = levels => [...Array(levels)].map((v, i) => '*'.repeat(i * 2 + 1).padStart(i + levels).padEnd(levels * 2 - 1));

console.log(starTowerNew(20));

StarTowerOld.js

function starTowerOld(levels) {
    const arr = [];
    
    for(let i = 0; i < levels; i++){
        arr.push('*'.repeat(i * 2 + 1).padStart(i + levels).padEnd(levels * 2 - 1));
    }
    
    return arr;
}

console.log(starTowerOld(20));