The best way to Clear up the Grouped by Commas Problem in Javascript

The problem

End the answer in order that it takes an enter n (integer) and returns a string that’s the decimal illustration of the quantity grouped by commas after each 3 digits.

Assume: 0 <= n < 2147483647

Examples:

       1  ->           "1"
      10  ->          "10"
     100  ->         "100"
    1000  ->       "1,000"
   10000  ->      "10,000"
  100000  ->     "100,000"
 1000000  ->   "1,000,000"
35235235  ->  "35,235,235"

The answer in Javascript

Possibility 1:

perform groupByCommas(n) {
  return n.toLocaleString()
}

Possibility 2:

perform groupByCommas(n) {
  return n.toString().change(/B(?=(d{3})+(?!d))/g, ",");
}

Possibility 3:

perform groupByCommas(n) {
  var s = n.toString(),
      r = [];
  s = reverse(s);
  for (var i = 0, l = s.size; i < l; i += 3) {
    r.push(s.substr(i, 3));
  }
  return reverse(r.be part of(','));
}
perform reverse(s) {
  return s.cut up('').reverse().be part of('');
}

Take a look at circumstances to validate our answer

describe("Assessments", () => {
  it("check", () => {
    Take a look at.assertEquals(groupByCommas(1), '1');
    Take a look at.assertEquals(groupByCommas(10), '10');
    Take a look at.assertEquals(groupByCommas(100), '100');
    Take a look at.assertEquals(groupByCommas(1000), '1,000');
    Take a look at.assertEquals(groupByCommas(10000), '10,000');
    Take a look at.assertEquals(groupByCommas(100000), '100,000');
    Take a look at.assertEquals(groupByCommas(1000000), '1,000,000');
    Take a look at.assertEquals(groupByCommas(35235235), '35,235,235');
  });
});