/** Filter false values off an Array.
 * Why it works, simply `filter` evaluates the return of the iterator function to a boolean
 * if the value is true will return the current item and the opposite for false.
 * Misunderstanding happens when you think you will have to explictly return a boolean like
 * `return currentItem === 'someValue' ` but actually if you returned any value it will be converted to a boolean
 * just like doing `!!currentItem`
 * so you can have a shorter version of filtering like below
**/
var a =  [0, 1, 2, 3, 'amin', '', false, NaN]

a.filter(x => x); // [1, 2, 3, "ate"]
a.filter(x => !x); // [0, "", false, NaN]

// or that way
a.filter(function(x){
  return x;
});

/* Using lodash
 * _.identity is a no-op function which just returns what is passed to it
 */
_.filter(a, _.identity); // [1, 2, 3, "ate"]
_.compact(a) // or just that simply.