Difficulties converting to Swift 3

Question

After converting from Swift 2 to Swift 3 (even after converting edit-> convert -> to current swift syntax) I am getting lots of errors. Especially:

I am shown total 90 errors for my project which was working fine in Swift 2 before i downloaded this beta Xcode 8.0 and converted to Swift 3

Is this a conversion mistake I am making?

@EricD i want to know is the method to convert code i use edit-> convert -> to current swift syntax is correct or not. If there is a better method then just to help me with that. thats all i asked for. — niravdesai21, Jun 21 '16 at 14:44
@niravdesai21 Yes this is the right command. This command does most of the work, but it's up to you to do the rest. Xcode is just an IDE, not a magical thing. :) Read the Swift 3 docs if you're lost with the changes. — Eric Aya, Jun 21 '16 at 14:48
Also, it is possible that the conversion didn't work right. Try converting it again, even if it gives you a warning that the file was already converted to Swift 3 — Pranav Wadhwa, Oct 07 '16 at 13:32
I had over a 100 errors when I converted. Come to find about 80% of the errors were resolved when I updated my libraries. In particular I was using Swifty JSON. I uploaded the latest file version and voilà, the rest was manageable stepping through code. — DG7, Aug 03 '17 at 21:53

Pranav Wadhwa · Accepted Answer · 2016-12-28T23:42:49.683

185

Most of them are easy fixes, simply by tapping the red button, and having Xcode fix it for you! Others include:

CGRect

Swift 2:

let frame = CGRectMake(0, 0, 20, 20)

Swift 3:

let frame = CGRect(x: 0, y: 0, width: 20, height: 20)

CGPoint

Swift 2:

let point = CGPointMake(0, 0)

Swift 3:

let point = CGPoint(x: 0, y: 0)

CGSize

Swift 2:

let size = CGSizeMake(20, 20)

Swift 3:

let size = CGSize(width: 20, height: 20)

CGRectGetMidX

Swift 2:

CGRectGetMidX(view)

Swift 3:

view.midX

CGRectGetMidY

Swift 2:

CGRectGetMidY(view)

Swift 3:

view.midY

UIColor

Swift 2:

let color = UIColor.redColor()

Swift 3:

let color = UIColor.red

"NS"

Swift 2:

NSTimer
NSData
NSError

Swift 3:

Timer
Data
Error

UserDefaults

Swift 2:

NSUserDefaults.standardUserDefaults().//something

Swift 3:

UserDefaults.standard.//something

edited Dec 28 '16 at 23:42

answered Jun 21 '16 at 16:57

Pranav Wadhwa

This helped me out a lot, while I was working I found one more that was a recurring change **CGRectGetMidX && CGRectGetMidY** Swift 2: CGRectGetMidX(object) || CGRectGetMidY(object) Swift 3: object.midX || object.midY – Tyler Hackbart Dec 28 '16 at 23:21
Thanks @TylerHack I'll include that in my answer. Glad to help! – Pranav Wadhwa Dec 28 '16 at 23:39
i have hundreds of CGRectMake etc, how is that easy to change? maybe by regexp, but even so quite dangerous – nights Feb 20 '17 at 10:22
@nights try converting it again. I believe the default conversion will fix it. – Pranav Wadhwa Feb 20 '17 at 13:49
tried a hundred times and it will not convert anything :[ now making changes manually...counting days – nights Feb 22 '17 at 14:32
Also size, point and rect with 0 as the values, it can be done like this. – Vitya Shurapov Jul 20 '17 at 13:29
let size = CGSize.zero, let point = CGPoint.zero, let rect = CGRect.zero – Vitya Shurapov Jul 20 '17 at 13:31

score 12 · Answer 2 · answered Oct 12 '16 at 10:11

12

And always remember to use the helpful "Fix all in Scope" function which can be found at Editor -> Fix all in Scope

answered Oct 12 '16 at 10:11

Sierra101

score 1 · Answer 3 · answered Jan 03 '17 at 12:06

I was converting a project and Xcode was not helping me with any fixes so I resorted to a couple of regex search-and-replaces:-

CGPointMake\((.*),[ ]*([^\)]+)\)
CGPoint(x:$1, y:$2)

CGSizeMake\((.*),[ ]*([^\)]+)\)
CGSize(width:$1, height:$2)

Note they are not aware of nested parentheses , but probably good enough for 90% of cases.

3 Answers3