Swift: Sort array of objects alphabetically - ios

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.

Answer 1

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)
}

Answer 2

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]
*/

Answer 3

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

Answer 4

For those using Swift 3, the equivalent method for the accepted answer is:
movieArr.sorted { $0.Name < $1.Name }

Answer 5

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

Answer 6

Sorted array
Swift 4.2
arrayOfRaces = arrayOfItems.sorted(by: { ($0["raceName"] as! String) < ($1["raceName"] as! String) })

Answer 7

*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!
}*