Javascript: use of Array#some and Array#every on nested array elements

Question

I have this key/value object:

{
   "march 2021 - monday": [
      {
         "day": "MONDAY",
         "date": "2021-03-01",
         "timetables": [
            {
               "day": "MONDAY",
               "slots": [
                  "09:00 - 09:30",
                  "09:30 - 10:00",
                  ...
               ],
               "changed": false
            },
            {
               "day": "MONDAY",
               "slots": [
                  "14:00 - 14:30",
                  "14:30 - 15:00",
                  ...
               ],
               "changed": false
            }
         ]
      },
      {
         "day": "MONDAY",
         "date": "2021-03-08",
         "timetables": [
            {
               "day": "MONDAY",
               "slots": [
                  "09:00 - 09:30",
                  "09:30 - 10:00",
                  ...
               ],
               "changed": false
            },
            {
               "day": "MONDAY",
               "slots": [
                  "14:00 - 14:30",
                  "14:30 - 15:00",
                  ...
               ],
               "changed": false
            }
         ]
      }
   ],
   "march 2021 - tuesday": [
      {
         "day": "TUESDAY",
         "date": "2021-03-09",
         "timetables": [
            {
               "day": "TUESDAY",
               "slots": [
                  "07:00 - 07:30",
                  "07:30 - 08:00",
                  ...
               ],
               "changed": false
            }
         ]
      }
   ],
   "march 2021 - thursday": [
      {
         "day": "THURSDAY",
         "date": "2021-03-18",
         "timetables": [
            {
               "day": "THURSDAY",
               "slots": [
                  "10:00 - 10:30",
                  "10:30 - 11:00",
                  ...
               ],
               "changed": false
            }
         ]
      }
   ]
}

I would like to:

• return true when there is a "changed": true for at least one timetable for every date property;
• otherwise return false;

I make this codepen where there are a couple of attempts. The second attempt seems to work but I'm not sure. Do you think this is correct? Is there another way to get what I want?

Thanks

Answer 1

I don't know, if I understand return true when there is a "changed": true for at least one timetable for every date property correctly, but the follwing seems to be a solution.

Your second attempt has the same logic, but lacks a little bit of structure

console.clear()

const portalDays = {
   'march 2021 - monday': [
      {
         day: 'MONDAY',
         date: '2021-03-01',
         timetables: [
            {
               day: 'MONDAY',
               slots: [
                  '09:00 - 09:30',
                  '09:30 - 10:00'
               ],
               changed: false
            },
            {
               day: 'MONDAY',
               slots: [
                  '14:00 - 14:30',
                  '14:30 - 15:00'
               ],
               changed: false
            }
         ]
      },
      {
         day: 'MONDAY',
         date: '2021-03-08',
         timetables: [
            {
               day: 'MONDAY',
               slots: [
                  '09:00 - 09:30',
                  '09:30 - 10:00'
               ],
               changed: false
            },
            {
               day: 'MONDAY',
               slots: [
                  '14:00 - 14:30',
                  '14:30 - 15:00'
               ],
               changed: false
            }
         ]
      }
   ],
   'march 2021 - tuesday': [
      {
         day: 'TUESDAY',
         date: '2021-03-09',
         timetables: [
            {
               day: 'TUESDAY',
               slots: [
                  '07:00 - 07:30',
                  '07:30 - 08:00'
               ],
               changed: false
            }
         ]
      }
   ],
   'march 2021 - thursday': [
      {
         day: 'THURSDAY',
         date: '2021-03-18',
         timetables: [
            {
               day: 'THURSDAY',
               slots: [
                  '10:00 - 10:30',
                  '10:30 - 11:00'
               ],
               changed: false
            }
         ]
      }
   ]
};

/*
  this second attempt it might be correct but I'm not sure
*/
{
  // Use small functions that do one thing
  const timeTableHasChanged = tt => hasChanged = tt.changed === true
  
  
  const dayhasChanged = day => day.timetables.some(timeTableHasChanged)

  
  const portalHasChanged = pd => {
    // Use `values()` not `keys()`. You are not interested in the keys here
    const pdv = Object.values(pd)
    // early return on empty input, so you don't have too many nested conditionals
    if (pdv.length === 0) {
      return true; // maybe false. Depends on what you want, if the inpout is empty
    }
    return pdv.every(item => item.every(dayhasChanged))
  }
 
  
  console.log(portalHasChanged(portalDays)) // should by false
  
  portalDays['march 2021 - monday'][0].timetables[0].changed = true
  portalDays['march 2021 - monday'][1].timetables[1].changed = true
  portalDays['march 2021 - tuesday'][0].timetables[0].changed = true
  portalDays['march 2021 - thursday'][0].timetables[0].changed = true

  console.log(portalHasChanged(portalDays)) // should be true

}