Reverse a String - Code not perfect

JavaScript
1

Tell us what’s happening:
Hey, please let me know how to write this more eloquently and foremost, pass the challenge.

Your code so far


function reverseString(str) {
let arr=[];
for (let i=0; i>str.length; i++) {
arr.unshift(str.i);
}
let reversed = arr.toString();
reversed.replace(/[\s,]+/g,'').trim();
return reversed;
}

reverseString("hello");

Your browser information:

User Agent is: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/68.0.3440.106 Safari/537.36.

Link to the challenge:
https://learn.freecodecamp.org/javascript-algorithms-and-data-structures/basic-algorithm-scripting/reverse-a-string

3

Unfortunately I only get “undefined”, and I don’t know what to make of that…