Lodash or JS GroupBy and Count for array of arrays

Question

I have a input :

results = [
    [ "Mon Nov 14 08:08:14 GMT+07:00 2016", "Ian Warner", "[email protected]", "DryKISS1", "small", "SW192EZ", "undefined" ],
    [ "Mon Nov 14 08:08:14 GMT+07:00 2016", "Ian Warner", "[email protected]", "DryKISS2", "large", "SW192EZ", "undefined" ],
    [ "Mon Nov 14 08:08:14 GMT+07:00 2016", "Ian Warner", "[email protected]", "DryKISS2", "large", "SW192EZ", "undefined" ],
    [ "Mon Nov 14 08:08:14 GMT+07:00 2016", "Ian Warner", "[email protected]", "DryKISS2", "medium", "SW192EZ", "undefined" ],
]

I want the output to be something like

small
  DryKISS1 : 1
medium
  DryKISS2 : 1
large
  DryKISS1 : 5
  DryKISS2 : 2
  DryKISS3 : 1

Basically grouping by size and then summing a company name in the same size bracket.

I have been playing with the below, but get lost as most of the examples are for hashes / objects

console.log _.chain( results ).groupBy( 4 ).map( ( value, key ) ->
  [
    key
    _.reduce( value, ( ( result, currentObject ) ->
      {
        company: result[ 3 ]
      }
    ))
  ]
).value()

Any help appreciated

Could you explain more detail how you expect your supplied data, to become your expected output, as I'm no seeing it. For starters I can't see any DryKISS3 in your supplied data. Also is that you real email address, if so you do know scrappers could grab this and your going to get spammed.. :) — Keith
– Keith, Commented Nov 14, 2016 at 17:03

Ori Drori · Accepted Answer · 2016-11-14 18:00:00Z

5

Group by the 4th column, then use transform to count the items by the 3rd column:

var data = [
  ["Mon Nov 14 08:08:14 GMT+07:00 2016", "Ian Warner", "[email protected]", "DryKISS1", "small", "SW192EZ", "undefined"],
  ["Mon Nov 14 08:08:14 GMT+07:00 2016", "Ian Warner", "[email protected]", "DryKISS2", "large", "SW192EZ", "undefined"],
  ["Mon Nov 14 08:08:14 GMT+07:00 2016", "Ian Warner", "[email protected]", "DryKISS2", "large", "SW192EZ", "undefined"],
  ["Mon Nov 14 08:08:14 GMT+07:00 2016", "Ian Warner", "[email protected]", "DryKISS2", "medium", "SW192EZ", "undefined"],
];
  
var result = _(data)
  .groupBy(4)
  .transform(function(result, items, key) {
    result[key] = _.countBy(items, 3);
  })
  .value();
  
console.log(result);

<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.0/lodash.min.js"></script>

answered Nov 14, 2016 at 18:00

Ori Drori

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1 Comment

Ian Warner Over a year ago

Many thx I chose the JS version below but gave you an upvote also.

Nina Scholz · Accepted Answer · 2016-11-15 08:08:03Z

1

In plain Javascript, you could use an object with nested properties for the count.

var results = [["Mon Nov 14 08:08:14 GMT+07:00 2016", "Ian Warner", "[email protected]", "DryKISS1", "small", "SW192EZ", "undefined"], ["Mon Nov 14 08:08:14 GMT+07:00 2016", "Ian Warner", "[email protected]", "DryKISS2", "large", "SW192EZ", "undefined"], ["Mon Nov 14 08:08:14 GMT+07:00 2016", "Ian Warner", "[email protected]", "DryKISS2", "large", "SW192EZ", "undefined"], ["Mon Nov 14 08:08:14 GMT+07:00 2016", "Ian Warner", "[email protected]", "DryKISS2", "medium", "SW192EZ", "undefined"]],
    grouped = {};

results.forEach(function (a) {
    grouped[a[4]] = grouped[a[4]] || {};
    grouped[a[4]][a[3]] = (grouped[a[4]][a[3]] || 0) + 1;
});

console.log(grouped);

With max count

var results = [["Mon Nov 14 08:08:14 GMT+07:00 2016", "Ian Warner", "[email protected]", "DryKISS1", "small", "SW192EZ", "undefined"], ["Mon Nov 14 08:08:14 GMT+07:00 2016", "Ian Warner", "[email protected]", "DryKISS2", "large", "SW192EZ", "undefined"], ["Mon Nov 14 08:08:14 GMT+07:00 2016", "Ian Warner", "[email protected]", "DryKISS2", "large", "SW192EZ", "undefined"], ["Mon Nov 14 08:08:14 GMT+07:00 2016", "Ian Warner", "[email protected]", "DryKISS2", "medium", "SW192EZ", "undefined"]],
    grouped = {},
    max = { count: 0, keys: [] };

results.forEach(function (a) {
    grouped[a[4]] = grouped[a[4]] || {};
    grouped[a[4]][a[3]] = (grouped[a[4]][a[3]] || 0) + 1;
    if (grouped[a[4]][a[3]] > max.count) {
        max = { count: grouped[a[4]][a[3]], keys: [{ size: a[4], group: a[3] }] };
        return;
    }
    if (grouped[a[4]][a[3]] === max.count) {
        max.keys.push = { size: a[4], group: a[3] };
    }
});

console.log(max);
console.log(grouped);

.as-console-wrapper { max-height: 100% !important; top: 0; }

edited Nov 15, 2016 at 8:08

answered Nov 14, 2016 at 17:08

Nina Scholz

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5 Comments

Keith Over a year ago

I want the output to be something like, doesn't look the same. :) It's most likely what he's after, but would be nice if OP's made the data source and expected results, reproducible.

Ian Warner Over a year ago

Excellent thanks - I was trying to find a loDash way, but this is a simple vanilla method that should be used I feel.

Ian Warner Over a year ago

Ahh one issue, how would I sort these so count is top?

Nina Scholz Over a year ago

object have no order. you yould get the keys in an array and sort the array. while youn have two levels, you need to sort the nesed level as well.

Ian Warner Over a year ago

Wow - seems the sort is more complex then the iteration... many thanks, hope this helps others. Seems when I do a search for Array grouping I get so many replies that contain objects / collections or hashes depends on language

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