Is there an easy way to make nested array flat?

Question

That is to make this:

[ [\'dog\',\'cat\', [\'chicken\', \'bear\'] ],[\'mouse\',\'horse\'] ]

into:

[\'dog\',\'cat\',\'chicken\',\'

Answer 1

var flattened = [[0, 1], [2, 3], [4, 5]].reduce(function(a, b) {
  return a.concat(b);
});
// flattened is [0, 1, 2, 3, 4, 5]

It's note worthy that reduce isn't supported in IE 8 and lower.

developer.mozilla.org reference