Reverse decimal digits in javascript

Question

How do I reverse the digits of a number using bitwise?

input:

x = 123; 

output:

x = 321; 

Answer 1

Memory Usage: 35.3 MB, less than 100.00% of JavaScript online submissions for Reverse Integer on leetcode.com. Runtime: 80 ms, faster than 61.48% of JavaScript online submissions for Reverse Integer.

Time complexity is O(log10(n)).

function reverse(x) {
  let rev = 0;
  const isNegative = Math.sign(x) === -1;
  const isOverflow = n => n > 2**31;
  x = Math.abs(x);

  while (x) {
    let pop = x % 10;
    x = Math.floor(x / 10);
    rev = rev * 10 + pop;

    if (isOverflow(rev)) {
      return 0;
    } 
  }

  return isNegative ? rev * -1 : rev;
}