How to sort by increasing order an array of objects based on its properties - Swift

Question

I'm having some problem in sorting an array of objects:

class Genome {

var id: Float?
var won: Float?
var lost: Float?
var drew: Float?

var fitness: Int = Int.random(in: 0...100)

init(id: Float, won: Float, lost: Float, drew: Float) {
    self.id = id
    self.won = won
    self.lost = won
    self.drew = drew
  }
}

This is the object. I have an array of 50 "Genome" objects and I need to sort it using its fitness property.

I already tried this:

genomes.sorted({ $0.fitness > $1.fitness })

But it didn't work. How can I do that?

Answer 1

sorted has a return value. You have to declare a new variable and in creasing order is <

let sortedGenomes = genomes.sorted{ $0.fitness < $1.fitness }

To sort genomes in place use sort

genomes.sort{ $0.fitness < $1.fitness }

Side note: Don't declare properties as optional which are initialized with non-optional values.

Answer 2

Swift 3 & Swift 4 & Swift 5

This will sort your object array in ascending order.

let sortedGenomes = genomes.sorted(by: { $0.fitness < $1.fitness })