尝试使用 确定输入字符串是否是有效的电话号码CharacterSet
。似乎isSubset
工作正常,但isSuperset
会崩溃。
我认为这是Foundation中的一个错误。
let phoneNumberCharacterSet = CharacterSet(charactersIn: "01234567890,;*+#").union(CharacterSet.whitespaces)
let zeroCharacterSet = CharacterSet(charactersIn: "0")
if zeroCharacterSet.isSubset(of: phoneNumberCharacterSet) {
print("zero is a subset of the phone number set")
}
if phoneNumberCharacterSet.isSuperset(of: zeroCharacterSet) {
// will never get here due to crash
print("is a superset of '0'")
}