can't print array of objects with forEach node js code example

Example 1: js loop through associative array

var months = [];
months["jan"] = "January";
months["feb"] = "February";
months["mar"] = "march";

for (var key in months) {
    var value = months[key];
    console.log(key, value);
}

Example 2: perform a function on each element of array javascript

var new_array = old_array.map(function(e) { 
  e.data = e.data.split(','); 
  return e;
});