Swift3 optionals chaining in IF conditions bug?

Question

This code worked just fine in Swift 2.3 and I don't understand why I have to unwrap TestClass to check if number is bigger than 4. This is whole point of chaining optionals, to save additional call.

Now to make this work, I have to check if testClass != nil (or use implicit unwrap with if let statement) and then check count.

Is this really the only way?

import UIKit

class testClass
{
    var optionalInt:Int?
}

var test:testClass?

if test?.optionalInt > 4
{

}

Sorry about the bad news on this one, but very glad you asked about it, as this is liable to come up a lot in one form or another. — matt, Sep 10 '16 at 15:43
Related: http://stackoverflow.com/questions/39251005/strange-generic-function-appear-in-view-controller-after-converting-to-swift-3. — Martin R, Sep 10 '16 at 19:52

score 5 · Answer 1 · answered Sep 10 '16 at 15:41

It's not a bug. It is, alas, intentional. Implicit unwrapping of optionals in comparisons (>) has been removed from the language.

So, the problem now is that what's on the left side of the > is an Optional, and you can no longer compare that directly to 4. You have to unwrap it and get an Int, one way or another.

score 4 · Answer 2 · answered Sep 10 '16 at 15:42

First of all, where are you initialising your test var? Of course it'll be nil if you don't give it a value!

And regarding optional chaining, what's the issue writing :

if let optionalInt = test?.optionalInt, optionalInt > 4
{

}

As always, safety > brevity.

score 0 · Accepted Answer · answered Sep 10 '16 at 15:42

0

Optional comparison operators are removed from Swift 3. SE-0121

You need to write something like this:

if test?.optionalInt ?? 0 > 4
{

}

answered Sep 10 '16 at 15:42

OOPer

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score 0 · Answer 4 · answered Nov 21 '18 at 09:50

This could also happen on Guard statement. Example:

var playerLevels = ["Harry": 25, "Steve": 28, "Bob": 0]

for (playerName, playerLevel) in playerLevels {

guard playerLevels > 0 else {//ERROR !!
    print("Player \(playerName) you need to do the tutorial again !")
    continue
}

print("Player \(playerName) is at Level \(playerLevels)")

}

Swift3 optionals chaining in IF conditions bug?

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