删除Swift 2

Question

我有一个问题，就是在一个String中连接不同的String。代码有效，但我在每个字符串之间都插入了一个单词。提前感谢您的回复。

let locality = String(self.locality)
let postalCode = String(self.postalCode)
let administrativeArea = String(self.administrativeArea)
let country = String(self.country)

let addressFull = locality + ", " + postalCode + " " + administrativeArea + ", " + country
print(addressFull)

输出

Optional("..."), Optional("...") Optional("..."), Optional("...")

Answer 1

self.locality和您的其他属性是可选字符串，因此您必须在使用它们之前安全地打开它们。

if let的示例：

if let locality = String(self.locality), let postalCode = String(self.postalCode), let administrativeArea = String(self.administrativeArea), let country = String(self.country) {
    let addressFull = locality + ", " + postalCode + " " + administrativeArea + ", " + country
    print(addressFull)
}

你应该学习关于Optionals的文档，这是Swift中一个非常重要的概念。