[Answered ]-Counting Array Values by a Filtered Value in Javascript

var arr = [2, 2, 1.5, 1.5, 3, -2]
var result = arr.reduce(function(agg, item) {
  var key = "other";
  if (item < 1) key = "<1";
  if (item > 1 && item < 2) key = "1<2";
  if (item > 2) key = ">2";
  agg[key] = (agg[key] || 0) + 1
  return agg;
}, {})

console.log(result)