Swift3可选链在IF条件下出现错误? [英] Swift3 optionals chaining in IF conditions bug?

问题描述

这段代码在Swift 2.3中工作得很好，我不明白为什么我必须拆开TestClass来检查数字是否大于4.这是链接可选项的全部目的，以节省额外的调用.

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.

现在要执行此操作，我必须检查是否testClass != nil(或对if let语句使用隐式解包)，然后检查计数.

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

这真的是唯一的方法吗?

Is this really the only way?

import UIKit

class testClass
{
    var optionalInt:Int?
}

var test:testClass?

if test?.optionalInt > 4
{

}

推荐答案

可选比较运算符已从Swift 3中删除. SE-0121

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

您需要编写如下内容:

if test?.optionalInt ?? 0 > 4
{

}

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