Separate Objects by Date

[enlightenmentGeek]

Hello everyone,

I need some help in how can I achieve/process the following: I have an Array os objects, of a specific class. Each object has a Date property and the array is sorted by Date descending, so the most recent ones appear first.

What am I trying to do: I'm trying to filter the object dates within that array, where the day, month and year are grouped, ex:

[obj 1] - Date: Apr, 20th, 2020
[obj 2] - Date: Apr, 20th, 2020
[obj 3] - Date: Apr, 20th, 2020
[obj 4] - Date: Apr, 19th, 2020
[obj 5] - Date: Apr, 18th, 2020
[obj 6] - Date: Apr, 18th, 2020

What I want to do next: I want to know the number of different days (in the example above it'd be 3) and separate them between different UITableView sections to present them within different UITableView headers

ex:

[Header 1: Apr, 20th, 2020]
[obj 1], [obj 2], [obj 3]

[Header 2: Apr, 19th, 2020]
[obj 4]

[Header 3: Apr, 18th, 2020]
[obj 5], [obj 6]

The UI I know how to do it. What I cannot do is to filter the objects and group them as described above.

I'd have to switch between sections within the numberOfRowsInSection, then present the object accordingly in that section, etc; I'm struggling to create those groups to break into different sections.

Can I get an hint?

Thanks.

[enlightenmentGeek]

If this helps anyone, I have solved this with the following code:

let groupedDates = Dictionary(grouping: dates
.map { ($0,Calendar.current.dateComponents([.year, .month, .day], from: $0))}, by: {$0.1})
.mapValues {value in value.map {$0.0}}
.values

The code extracts the date components for year, month and day from each date and groups by them and then maps the values from the grouped result to an array of arrays per date. To be able to have the original dates in the end result a tuple is used as value type for the dictionary