Reversing a string in javascript

Reversing a string is not always as straight forward as the term indicates.

method 1

1const stringReverse = (s) => {
2  let str = "";
3  for (let i = s.length - 1; i >= 0; i--) {
4    str += s[i];
5  }
6  return str;
7};

method 2

1const stringReverse = (s) => {
2  let str = [];
3  for (let i = s.length - 1, j = 0; i >= 0; i--, j++) {
4    str[j] = s[i];
5  }
6  return str.join("");
7};

method 3 : Using built in split(), reverse() and join() methods

1const stringReverse = (s) => {
2  return s.split("").reverse().join("");
3};

method 4 : Looping through each character

1const stringReverse = (s) => {
2  let reversed = "";
3
4  for (let character of s) {
5    reversed = character + reversed;
6  }
7  return reversed;
8};

method 5 : Using reduce method

1const stringReverse = (s) => {
2  return s.split("").reduce((rev, char) => char + rev, "");
3};

conclusion

In terms of performance and efficient use of memory and space, I'd recommend using method 1, method 2 and method 4 as they are very performant.