flatten.js

flatten.js

// flatten an array 
// input [[[[1], 2, 3], 4, 5, 6, 7], 8, 9, 10, [11, 12, 13]]
// output [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13]

var flatten = function(e){
  var flatArray = []; 
  if (!Array.isArray(e)) {
    flatArray = flatArray.concat(e);
  } else {
    for (var i = 0; i < e.length; i++) {
      flatten(e[i]); 
    }
  }
}