jQuery equivalent of underscore.js' groupBy

Question

Is there a built in function in jQuery that does the equivalent of http://underscorejs.org/#groupBy ?

Any workarounds?

Thanks

There is no jQuery equivalent built in. Feel free to create one yourself and share it though. — Kevin B, Jan 07 '13 at 20:49
I wanted to hack around a jQuery alternative but I was quickly discouraged — Alexander, Jan 07 '13 at 21:48
Possible duplicate of [jquery array group by](http://stackoverflow.com/questions/14427659/jquery-array-group-by) — 200_success, Mar 01 '16 at 18:47

Bergi · Accepted Answer · 2016-11-14T14:48:24.040

7

No. jQuery was not made for data handling, but for DOM, Ajax and Animations - those utility functions as each, map or grep which are needed internally suck.

Use Underscore, there is nothing wrong with it! If you don't want to load the whole script, you can easily copy the groupby function from the source to wherever you need it. Don't forget to add a comment on its origin.

edited Nov 14 '16 at 14:48

answered Jan 07 '13 at 20:51

Bergi

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score 2 · Answer 2 · edited May 23 '17 at 12:25

Here is a jQuery adaptation of squint's native Javascript answer:

$.fn.groupBy = function(predicate) {
  var $array = $(this),
      grouped = {};

  $.each($array, function (idx, obj) {
    var $obj = $(obj);
        groupKey = predicate($obj);
    if (typeof(grouped[groupKey]) === "undefined") {
      grouped[groupKey] = $();
    }
    grouped[groupKey] = grouped[groupKey].add($obj);
  });

  return grouped;
}

^This returns a hash of { key_name: jQueryObjects }

And usage, in this case, to group elements ($yourElements) by the HTML name attribute:

var groupedByName = $yourElements.groupBy(function (obj) {
  return $(obj).attr('name');
});

score 0 · Answer 3 · answered Jan 22 '20 at 09:18

I've used this, and it worked for me perfectly

function groupBy(array, keyOrIterator) {
  var iterator, key;

  // use the function passed in, or create one
  if(typeof key !== 'function') {
    key = String(keyOrIterator);
    iterator = function (item) { return item[key]; };
  } else {
    iterator = keyOrIterator;
  }

  return array.reduce(function (memo, item) {
    var key = iterator(item);
    memo[key] = memo[key] || [];
    memo[key].push(item);
    return memo;
  }, {});
}

from Link

jQuery equivalent of underscore.js' groupBy

3 Answers3

^This returns a hash of { key_name: jQueryObjects }

Linked