Welcome to the Treehouse Community

Want to collaborate on code errors? Have bugs you need feedback on? Looking for an extra set of eyes on your latest project? Get support with fellow developers, designers, and programmers of all backgrounds and skill levels here with the Treehouse Community! While you're at it, check out some resources Treehouse students have shared here.

Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and join thousands of Treehouse students and alumni in the community today.

Start your free trial

iOS Swift Closures Closures and Closure Expressions Using the Sorted Function

Posted by NOUR A ALGHAMDI
NOUR A ALGHAMDI
Courses Plus Student 5,607 Points

please i need an explain and help :\

good evening guys :) can some one explain to me , What is the benefit of writing this code : 

let sortedNames = names.sort{(S1: String ,S2: String) -> Bool in return S1 > S2})

beside my code doesn't work :( can you help me how to fix it ?!

2 Answers

Jhoan Arango
Jhoan Arango
14,575 Points
Jhoan Arango
Jhoan Arango
14,575 Points

Hello:

The benefit of writing this code, is that you can don't have to create a full function, and then pass it as the arguement to the sort() method. Meaning that you write less.. For example.

// Array of names
var  names = ["Jhoan", "Harold","Carlos"]

// Function that sorts the names in order.
func sortNames(name1: String, name2: String) -> Bool {
   return name1 < name2
}
// Passing the function as the argument for the sort() method. 
let sortedNames = names.sort(sortNames)


// So instead of writing all this code, we can just use a closure, which is basically the same.

let sortedNames = names.sort { (S1: String, S2: String) -> Bool in return S1 < S2 }

Hope this helps you a bit

I recommend reading closures in this book

Aaron saunders
Aaron saunders
1,969 Points
Aaron saunders
Aaron saunders
1,969 Points 
    // you can even shrink the closure using 
    // Closure arguments can be references by position ($0, $1, ...) rather than by name
    let sortedNames2 = names.sort { $0 < $1 }
    print(sortedNames2)
Jhoan Arango
Jhoan Arango
14,575 Points
Jhoan Arango
Jhoan Arango
14,575 Points

That is right.. but to make it even shorter, you can do this

let sortedNames = names.sort(>)

So, you write even less code.