小编Mun*_*han的帖子

当我flatMap与String类型数组一起使用时，它没有给出任何警告，而在Int类型数组的情况下它给出了警告。为什么？例：

let strings = [
    "I'm excited about #SwiftUI",
    "#Combine looks cool too",
    "This year's #WWDC was amazing"
]
strings.flatMap{$0 + "."} //No warning

let ints = [
   2,3,4
]
ints.flatMap{$0 + 1} //'flatMap' is deprecated: Please use compactMap(_:) for the case where closure returns an optional value