Sectioning a tableview by dates from a dictionary

Question

I have a dictionary that contains a key/value pair of a Date that contains an array of my custom object Meals grouped together by the same dates.

Meal Object:

Answer 1

Create a struct for the sections

struct Section {
    let date : Date
    let meals : [Meal]
}

and map the grouped dictionary to an array of Section

var sections = [Section]()

let sortedDates = self.grouped.keys.sorted(>)
sections = sortedDates.map{Section(date: $0, meals: self.grouped[$0]!)}

You could add a date formatter to display the Date instance more meaningful.

The table view data source methods are

override func numberOfSections(in tableView: UITableView) -> Int {
    return sections.count
}

override func tableView(_ tableView: UITableView, titleForHeaderInSection section: Int) -> String? {        
    return sections[section].date.description
}

override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
    return sections[section].meals.count
}

override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    let cell = tableView.dequeueReusableCell(withIdentifier: "foodCell", for: indexPath)
    let meal = sections[indexPath.section].meals[indexPath.row]
    ...

Note:

Consider to use less optionals and a struct rather than a NSObject subclass. Unlike NSCoding Codable does not require to conform to NSObjectProtocol. And never declare properties as implicit unwrapped optional.