Better way of iterating through array of custom struct

Question

This is my custom data struct:

struct Absence {
    var type: String
    var date: TimeInterval
}

I have an array of this data struct like this:

var absences: [Absence]

I would like a function to return all the types of an absence. I have written this:

func types() -> [String] {
    var types = [String]()
    for absence in self.absences {
        if !types.contains(absence.type) {
            types.append(absence.type)
        }
    }
    return types
}

I was wondering if there was a better way of iterating through using either map, compactMap or flatMap. I am new to mapping arrays. Any help much appreciated.

Start with absences.map { $0.type }. Use a Set to get rid of duplicates. — Martin R
– Martin R, Commented Sep 4, 2020 at 19:36

finebel · Accepted Answer · 2020-09-04 19:44:30Z

1

You could just do the following:

var types = absences.map { $0.type }

If you would like to filter the types:

var types = absences.map { $0.type }.filter { $0.contains("-") }

Or if you simply want to remove all duplicates:

var types = Array(Set(absences.map { $0.type }))

answered Sep 4, 2020 at 19:44

finebel

2,3531 gold badge11 silver badges23 bronze badges

Sign up to request clarification or add additional context in comments.

4 Comments

Leo Dabus Over a year ago

Swift 5.2 or later you can use KeyPath map(\.type)

pawello2222 Over a year ago

@LeoDabus Was actually writing the same :)

Leo Dabus Over a year ago

Note that using a set like this you will discard the array original order. If you would like to preserve the original order of the elements check this post stackoverflow.com/a/34712330/2303865

Tahmid Azam Over a year ago

Thank you everyone for your solutions - much appreciated!

Collectives™ on Stack Overflow

Better way of iterating through array of custom struct

1 Answer 1

4 Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

4 Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related