Iterative solution for flattening n-th nested arrays in Javascript

Question

Can anyone show me an iterative solution for the following problem? I solved it recursively but struggled with an iterative solution. (Facebook Technical Interv

Answer 1

How about this?

inp = [1, {a: 2}, [3], [[4, 5], 6], 7]
out = inp;

while(out.some(Array.isArray))
  out = [].concat.apply([], out);

document.write(JSON.stringify(out));