Javascript Array Grouping (v10)

Revision 10 of this benchmark created by agershun on

Description

different methods for grouping string in an array and getting the max value of the grouping.

Preparation HTML

<script src="http://alasql.org/console/alasql.min.js"></script>
<script>
  var arr = [];
  var day, month, year;
  for (var i = 0; i < 30000; i++) {
    day = Math.round(Math.random() * 30);
    month = Math.round(Math.random() * 12);
    year = Math.round(Math.random() * 3 + 2009);
    arr.push(month + "/" + day + "/" + year);
  }
</script>

Test runner

Ready to run.

Testing in
TestOps/sec
nightcracker
var group = {};
var max = 0;
var value;
for (var i = arr.length; --i >= 0;) {
  value = arr[i];
  group[value] = (group[value] | 0) + 1;
}
for (key in group) {
  if (group[key] > max) max = group[key];
}
ready
Mike Samuel
var max = 0;
var group = {};
var value, n, len = arr.length;
for (var i = len; --i >= 0;) {
  value = arr[i];
  n = group[value] = 1 - -(group[value] | 0);
  if (n > max) {
    max = n;
  }
}
ready
Mike Samuel edited
var max = 0,
  group = {},
  value, n, len = arr.length;
for (var i = len; --i >= 0;) {
  value = arr[i];
  n = group[value] = 1 - -(group[value] | 0);
  if (n > max) {
    max = n;
  }
}
ready
Alasql
var max = alasql('SELECT MAX(cnt) FROM (SELECT COUNT([0]) AS cnt FROM [?] GROUP BY [0])', [arr]);
ready
Alasql (without array conversion)
var max = alasql('SELECT MAX(cnt) FROM (SELECT COUNT(*) AS cnt FROM ? GROUP BY _)', [arr]);
ready

Revisions

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