Is there a way to merge all these filters into one? Or another way to make it more effective? Or just use for loop?

 driving  = value.filter((obj) => obj.type === CalendarEventType.MIND && obj.data.practice === 'driving').length;
    breathWork  = value.filter((obj) => obj.type === CalendarEventType.MIND && obj.data.practice === 'breath work').length;
    meditation  = value.filter((obj) => obj.type === CalendarEventType.MIND && obj.data.practice === 'meditation').length;
    cooking  = value.filter((obj) => obj.type === CalendarEventType.MIND && obj.data.practice === 'cooking').length;
    walking  = value.filter((obj) => obj.type === CalendarEventType.MIND && obj.data.practice === 'walking').length;
    other  = value.filter((obj) => obj.type === CalendarEventType.MIND && obj.data.practice === 'other').length;

They look to me very redudant.

CodePudding user response：

Currently you're looping 6 times over the same array. You can reduce the runtime with a simple for-loop or reduce:

const counts = value.reduce((acc, el) => {
  if (el.type !== CalendarEventType.MIND) return acc;
  acc[el.data.practice] = (acc[el.data.practice] ?? 0)   1
  return acc;
}, {});

Example:

const CalendarEventType = {
  MIND: 1,
  OTHER: 2
};

const value = [
  {type: CalendarEventType.MIND, data: { practice: 'driving' } },
  {type: CalendarEventType.MIND, data: { practice: 'breath work' } },
  {type: CalendarEventType.OTHER, data: { practice: 'breath work' } },
  {type: CalendarEventType.MIND, data: { practice: 'other' } },
  {type: CalendarEventType.MIND, data: { practice: 'other' } },
  {type: CalendarEventType.OTHER, data: { practice: 'other' } },
];

const counts = value.reduce((acc, el) => {
  if (el.type !== CalendarEventType.MIND) return acc;
  acc[el.data.practice] = (acc[el.data.practice] ?? 0)   1
  return acc;
}, {});

console.log(counts);

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CodePudding user response：

One possible way would be to group by data.practice. Since there's no native "group by" function, you could implement it yourself (as described here), or you could use a library like Lodash or Ramda.

Example, using Lodash's groupBy:

const filteredItems = value.filter((obj) => obj.type === CalendarEventType.MIND);
const groupedItems = groupBy(filteredItems, obj => obj.data.practice);

Then you can do whatever you want with groupedItems, e.g.:

driving  = groupedItems['driving'] ? groupedItems['driving'].length : 0;

Note that if a given value for data.practice is not represented in filteredItems, then that key won't be present in groupedItems - hence the need to check for that key.

CodePudding user response：

You could take an array of values and use a single filter.

const
    practices = ['driving', 'breath work', 'meditation', 'cooking', 'walking', 'other'];
    filter = ({ type, data: { practice } }) => type === CalendarEventType.MIND && practices.includes(practice),
    result = value.filter(filter),
    count = values.reduce((sum, o) => sum   filter(o), 0);