functional-count-zeros.js

var not = function (fn) {
  return function () {
    return !fn.apply(this, arguments);
  };
};
var getIncremenentIfTrue = function (fn) {
  return function (count, predicate)  {
    if (fn(predicate)) ++count;
    return count;
  };
};

arr.reduce(getIncrementIfTrue(not(Boolean)), 0);