steamroller.js

// Bonfire: Steamroller
// Author: @codebubb
// Challenge: http://www.freecodecamp.com/challenges/bonfire-steamroller
// Learn to Code at Free Code Camp (www.freecodecamp.com)

function steamroller(arr) {
	var flattened = [];
	function flatten(a){
      return Array.isArray(a) ? a.forEach(flatten) : flattened.push(a);
    }
    flatten(arr);
	return flattened;
}