String.length Polyfill

String.prototype.lengthPolyfill = function () {
  let str = this;
  function findLength(str) {
    if (str === "") return 0;
    return 1 + findLength(str.slice(1));
  }
  return findLength(str);
};

console.log("Arjunan. K".length); // 10
console.log("Arjunan. K".lengthPolyfill()); // 10