CODEWITHSUNDEEP
javascriptlodash
Ian Warner
Ian Warner

Reputation: 1068

Lodash or JS GroupBy and Count for array of arrays

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

Upvotes: 2

Views: 1860

Answers (2)

Nina Scholz
Nina Scholz

Reputation: 386654

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; }

Upvotes: 1

Ori Drori
Ori Drori

Reputation: 191996

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>

Upvotes: 5

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