Add dynamic array objects from filtered data in Javascript

I have a dynamic data that I need to order and filter from each year, the data is as follows

years: ['2018', '2019', '2020', '2021', '2022']

[
 [{name: 'event_name1', created_at: 2021-01-12 11:25:0}, {name: 'event_name1', created_at: 2021-01-14 11:25:0}, {name: 'event_name1', created_at: 2020-01-12 11:25:0}, {name: 'event_name1', created_at: 2019-11-12 11:25:0}],

 [{name: 'event_name2', created_at: 2018-01-12 11:25:0}, {name: 'event_name2', created_at: 2018-01-12 11:25:0}, {name: 'event_name2', created_at: 2021-01-12 11:25:0}, {name: 'event_name2', created_at: 2021-11-12 11:25:0},{name: 'event_name2', created_at: 2022-01-12 11:25:0}]
 
... event_name3
]

(I must clarify that the years are taken previously according to the data information).

I have tried several things, using the map and filter methods together with the for structure, however, I am not able to filter the information like this. This is how I want the filtered data

[
{element: 'event_name1',data:[2018:0,2019:1,2020:1,2021:1,2022:0]},
{element: 'event_name2',data:[2018:2,2019:0,2020:0,2021:1,2022:1]}
]

CodePudding user response：

No reduce. But maps and filter.

I assume that the expected data property contains text values.

const data = [[ { name: 'event_name1', created_at: '2021-01-12 11:25:0' },{ name: 'event_name1', created_at: '2021-01-14 11:25:0' },{ name: 'event_name1', created_at: '2020-01-12 11:25:0' },{ name: 'event_name1', created_at: '2019-11-12 11:25:0' }],[{ name: 'event_name2', created_at: '2018-01-12 11:25:0' },{ name: 'event_name2', created_at: '2018-01-12 11:25:0' },{ name: 'event_name2', created_at: '2021-01-12 11:25:0' },{ name: 'event_name2', created_at: '2021-11-12 11:25:0' },{ name: 'event_name2', created_at: '2022-01-12 11:25:0' }]];

const years = ['2018', '2019', '2020', '2021', '2022'];

const result = data.map((arr) => {
   const [{ name: element }] = arr;
   const data = years.map((year) => {
      const count = arr.filter(({ created_at }) => created_at.slice(0, 4) === year).length;
      return `${year}:${count}`;
   });
   
   return { element, data };
})


console.log(result);

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

CodePudding user response：

Looks like a scenario to use the reduce method. Iterate over the events' array and create/modify the appropriate element in the accumulator.

CodePudding user response：

Here you go my friend

const baseYearsInstances = {
  '2018': 0,
  '2019': 0,
  '2020': 0,
  '2021': 0,
  '2022': 0,
};

const test = [
  [
    { name: 'event_name1', created_at: '2021-01-12 11:25:0' },
    { name: 'event_name1', created_at: '2021-01-14 11:25:0' },
    { name: 'event_name1', created_at: '2020-01-12 11:25:0' },
    { name: 'event_name1', created_at: '2019-11-12 11:25:0' },
  ],

  [
    { name: 'event_name2', created_at: '2018-01-12 11:25:0' },
    { name: 'event_name2', created_at: '2018-01-12 11:25:0' },
    { name: 'event_name2', created_at: '2021-01-12 11:25:0' },
    { name: 'event_name2', created_at: '2021-11-12 11:25:0' },
    { name: 'event_name2', created_at: '2022-01-12 11:25:0' },
  ],
];

const eventToDate = (event) => {
  const dataNotSorted = event.map((eventDate) => {
    const year = new Date(eventDate.created_at).getFullYear();
    return year;
  });

  const data = dataNotSorted.reduce(function (acc, curr) {
    return acc[curr] ?   acc[curr] : (acc[curr] = 1), acc;
  }, {});

  return { element: event[0]?.name, data: { ...baseYearsInstances, ...data } };
};

const result = test.map(eventToDate);

console.log(result);