mergeSortedArrays

Merges two sorted arrays into one.

• Use the spread operator (...) to clone both of the given arrays.
• Use Array.from() to create an array of the appropriate length based on the given arrays.
• Use Array.prototype.shift() to populate the newly created array from the removed elements of the cloned arrays.

const mergeSortedArrays = (a, b) => {
  const _a = [...a],
    _b = [...b];
  return Array.from({ length: _a.length + _b.length }, () => {
    if (!_a.length) return _b.shift();
    else if (!_b.length) return _a.shift();
    else return _a[0] > _b[0] ? _b.shift() : _a.shift();
  });
};

mergeSortedArrays([1, 4, 5], [2, 3, 6]); // [1, 2, 3, 4, 5, 6]