javascript - Lodash 或 JS GroupBy 和数组数组的计数

Question

我有一个输入:

results = [
    [ "Mon Nov 14 08:08:14 GMT+07:00 2016", "Ian Warner", "ian.warner@drykiss.com", "DryKISS1", "small", "SW192EZ", "undefined" ],
    [ "Mon Nov 14 08:08:14 GMT+07:00 2016", "Ian Warner", "ian.warner@drykiss.com", "DryKISS2", "large", "SW192EZ", "undefined" ],
    [ "Mon Nov 14 08:08:14 GMT+07:00 2016", "Ian Warner", "ian.warner@drykiss.com", "DryKISS2", "large", "SW192EZ", "undefined" ],
    [ "Mon Nov 14 08:08:14 GMT+07:00 2016", "Ian Warner", "ian.warner@drykiss.com", "DryKISS2", "medium", "SW192EZ", "undefined" ],
]

我希望输出是这样的

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

基本上按大小分组，然后在相同大小的括号中对公司名称求和。

我一直在玩下面的东西，但是因为大多数示例都是针对哈希/对象而迷路的

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

感谢任何帮助

Answer 1

按第 4 列分组，然后使用转换按第 3 列计算项目数:

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

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