NEW: Master Swift design patterns with my latest book! >>

How to sort an array using sort()

Written by Paul Hudson    @twostraws

All arrays have built-in sort() and sorted() methods that can be used to sort the array, but they are subtly different.

If the array is simple you can just call sort() directly, like this, to sort an array in place:

var names = ["Jemima", "Peter", "David", "Kelly", "Isabella"]
names.sort()

If you have a custom struct or class and want to sort them arbitrarily, you should call sort() using a trailing closure that sorts on a field you specify. Here's an example using an array of custom structs that sorts on a particular property:

struct MyCustomStruct {
    var someSortableField: String
}

var customArray = [
    MyCustomStruct(someSortableField: "Jemima"),
    MyCustomStruct(someSortableField: "Peter"),
    MyCustomStruct(someSortableField: "David"),
    MyCustomStruct(someSortableField: "Kelly"),
    MyCustomStruct(someSortableField: "Isabella")
]

customArray.sort {
    $0.someSortableField < $1.someSortableField
}

If you want to return a sorted array rather than sort it in place, use sorted() like this:

let sortedArray = customArray.sorted {
    $0.someSortableField < $1.someSortableField
}

Available from iOS 7.0

Did this solution work for you? Please pass it on!

Other people are reading…

About the Swift Knowledge Base

This is part of the Swift Knowledge Base, a free, searchable collection of solutions for common iOS questions.

Swift on the server is here

Get ahead of the game and learn server-side Swift with my latest book – build real-world projects while you learn!

Click here to visit the Hacking with Swift store >>