Swift: Sort array of objects alphabetically

Question

I have this:

class Movies {
  Name:String
  Date:Int
}

and an array of [Movies]. How do I sort the array alphabetically by name? I've tried:

movieArr = movieArr.sorted{ $0 < $1 }

and

movieArr = sorted(movieArr)

but that doesn't work because I'm not accessing the name attribute of Movies.

Joannes · Accepted Answer · 2022-09-08 08:18:21Z

392

In the closure you pass to sort, compare the properties you want to sort by. Like this:

movieArr.sorted { $0.name < $1.name }

or the following in the cases that you want to bypass cases:

movieArr.sorted { $0.name.lowercased() < $1.name.lowercased() }

Sidenote: Typically only types start with an uppercase letter; I'd recommend using name and date, not Name and Date.

Example, in a playground:

class Movie {
    let name: String
    var date: Int?
    
    init(_ name: String) {
        self.name = name
    }
}

var movieA = Movie("A")
var movieB = Movie("B")
var movieC = Movie("C")

let movies = [movieB, movieC, movieA]
let sortedMovies = movies.sorted { $0.name < $1.name }
sortedMovies

sortedMovies will be in the order [movieA, movieB, movieC]

Swift5 Update

channelsArray = channelsArray.sorted { (channel1, channel2) -> Bool in
            let channelName1 = channel1.name
            let channelName2 = channel2.name
            return (channelName1.localizedCaseInsensitiveCompare(channelName2) == .orderedAscending)
}

edited Sep 8, 2022 at 8:18

Joannes

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answered Nov 3, 2014 at 17:41

Mike S

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7 Comments

user2707185 Over a year ago

use movies.sort instead of movies.sorted @Mike S

Eric Aya Over a year ago

@julian-król You forgot to edit the other sorted to sort in the answer. Note: this is not a typo, sorted was correct in Swift 1 but has become sort in Swift 2.

Julian Over a year ago

thanks for explanation. Improved my edit, should be fine, please take a look :)

Matthieu Riegler Over a year ago

Beware, this won't work when sorting string that may or may not be capitalized. Comparing the .lowercaseString will solve this problem.

dvp.petrov Over a year ago

@EricAya Note it is sorted in Swift 3 again :D .

|

Imanou Petit · Accepted Answer · 2017-12-15 11:18:35Z

57

With Swift 3, you can choose one of the following ways to solve your problem.

1. Using `sorted(by:)` with a `Movie` class that does not conform to `Comparable` protocol

If your Movie class does not conform to Comparable protocol, you must specify in your closure the property on which you wish to use Array's sorted(by:) method.

Movie class declaration:

import Foundation

class Movie: CustomStringConvertible {

    let name: String
    var date: Date
    var description: String { return name }

    init(name: String, date: Date = Date()) {
        self.name = name
        self.date = date
    }

}

Usage:

let avatarMovie = Movie(name: "Avatar")
let titanicMovie = Movie(name: "Titanic")
let piranhaMovie = Movie(name: "Piranha II: The Spawning")

let movies = [avatarMovie, titanicMovie, piranhaMovie]
let sortedMovies = movies.sorted(by: { $0.name < $1.name })
// let sortedMovies = movies.sorted { $0.name < $1.name } // also works

print(sortedMovies)

/*
prints: [Avatar, Piranha II: The Spawning, Titanic]
*/

2. Using `sorted(by:)` with a `Movie` class that conforms to `Comparable` protocol

However, by making your Movie class conform to Comparable protocol, you can have a much concise code when you want to use Array's sorted(by:) method.

Movie class declaration:

import Foundation

class Movie: CustomStringConvertible, Comparable {

    let name: String
    var date: Date
    var description: String { return name }

    init(name: String, date: Date = Date()) {
        self.name = name
        self.date = date
    }

    static func ==(lhs: Movie, rhs: Movie) -> Bool {
        return lhs.name == rhs.name
    }

    static func <(lhs: Movie, rhs: Movie) -> Bool {
        return lhs.name < rhs.name
    }

}

Usage:

let avatarMovie = Movie(name: "Avatar")
let titanicMovie = Movie(name: "Titanic")
let piranhaMovie = Movie(name: "Piranha II: The Spawning")

let movies = [avatarMovie, titanicMovie, piranhaMovie]
let sortedMovies = movies.sorted(by: { $0 < $1 })
// let sortedMovies = movies.sorted { $0 < $1 } // also works
// let sortedMovies = movies.sorted(by: <) // also works

print(sortedMovies)

/*
 prints: [Avatar, Piranha II: The Spawning, Titanic]
 */

3. Using `sorted()` with a `Movie` class that conforms to `Comparable` protocol

By making your Movie class conform to Comparable protocol, you can use Array's sorted() method as an alternative to sorted(by:).

Movie class declaration:

import Foundation

class Movie: CustomStringConvertible, Comparable {

    let name: String
    var date: Date
    var description: String { return name }

    init(name: String, date: Date = Date()) {
        self.name = name
        self.date = date
    }

    static func ==(lhs: Movie, rhs: Movie) -> Bool {
        return lhs.name == rhs.name
    }

    static func <(lhs: Movie, rhs: Movie) -> Bool {
        return lhs.name < rhs.name
    }

}

Usage:

let avatarMovie = Movie(name: "Avatar")
let titanicMovie = Movie(name: "Titanic")
let piranhaMovie = Movie(name: "Piranha II: The Spawning")

let movies = [avatarMovie, titanicMovie, piranhaMovie]
let sortedMovies = movies.sorted()

print(sortedMovies)

/*
 prints: [Avatar, Piranha II: The Spawning, Titanic]
 */

edited Dec 15, 2017 at 11:18

answered Dec 19, 2015 at 11:45

Imanou Petit

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6 Comments

Kamaldeep singh Bhatia Over a year ago

Hey, Is there any diff. between 2nd and 3rd (except movies.sorted(by: <) and movies.sorted()) ?

Imanou Petit Over a year ago

sorted(by:) and sorted() are two different methods. You can use array.sorted() as an alternative for array.sorted(by: <).

Kamaldeep singh Bhatia Over a year ago

Yes, just asking in case of class definition do we need to change anything? I mean, can we have same class definition for both sorted(by:) and sorted() ?

Imanou Petit Over a year ago

Yes, you can have the same implementation of your class/struct that, in any case, has to conform to Comparable protocol.

Krunal Nagvadia Over a year ago

I have Array with customObject when i shoer in ascending order it's not shorting in proper way. "1" "14""28""31""4""42""49"

|

Maak · Accepted Answer · 2018-03-28 21:00:00Z

21

let sortArray =  array.sorted(by: { $0.name.lowercased() < $1.name.lowercased() })

edited Mar 28, 2018 at 21:00

Maak

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answered Mar 28, 2018 at 14:14

Marwan Alqadi

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2 Comments

Tom Tallak Solbu Over a year ago

adding .lowercased() worked for me after a long period of trying. I don't understand why, since all text were lowercased to begin with.

Marwan Alqadi Over a year ago

when use lowercased() will change all names to lower case to sorted properly :)

Jacobo Koenig · Accepted Answer · 2017-02-05 20:55:32Z

14

For those using Swift 3, the equivalent method for the accepted answer is:

movieArr.sorted { $0.Name < $1.Name }

answered Feb 5, 2017 at 20:55

Jacobo Koenig

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Comments

Eric · Accepted Answer · 2020-09-18 22:55:42Z

3

Most of these answers are wrong due to the failure to use a locale based comparison for sorting. Look at localizedStandardCompare()

answered Sep 18, 2020 at 22:55

Eric

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Comments

Srinivasan_iOS · Accepted Answer · 2019-04-25 13:05:17Z

1

Sorted array Swift 4.2

arrayOfRaces = arrayOfItems.sorted(by: { ($0["raceName"] as! String) < ($1["raceName"] as! String) })

answered Apr 25, 2019 at 13:05

Srinivasan_iOS

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Comments

Muhammad Ahmad · Accepted Answer · 2020-03-05 21:21:19Z

0

*import Foundation
import CoreData


extension Messages {

    @nonobjc public class func fetchRequest() -> NSFetchRequest<Messages> {
        return NSFetchRequest<Messages>(entityName: "Messages")
    }

    @NSManaged public var text: String?
    @NSManaged public var date: Date?
    @NSManaged public var friends: Friends?

}

    //here arrMessage is the array you can sort this array as under bellow 

    var arrMessages = [Messages]()

    arrMessages.sort { (arrMessages1, arrMessages2) -> Bool in
               arrMessages1.date! > arrMessages2.date!
    }*

answered Mar 5, 2020 at 21:21

Muhammad Ahmad

3984 silver badges9 bronze badges

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Swift: Sort array of objects alphabetically

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1. Using `sorted(by:)` with a `Movie` class that does not conform to `Comparable` protocol

2. Using `sorted(by:)` with a `Movie` class that conforms to `Comparable` protocol

3. Using `sorted()` with a `Movie` class that conforms to `Comparable` protocol

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1. Using `sorted(by:)` with a `Movie` class that does not conform to `Comparable` protocol

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