Swift

Question

我有一个包含 >2500 个客户姓名的列表，我想创建姓氏（姓氏的第一个字母）的字母索引。当姓氏前面有空格时（我知道遗留数据问题稍后应该得到修复），它们应该被删除。如果没有可用的姓氏，那么它应该作为 indexArrayro 中的最后一项出现。

结果应该是 indexArray == ["A","G","I","M","S","Z",""] 大写。

这是我目前得到的。

struct MyObject {
    let firstName: String
    let lastName : String
}

let objectArray : [MyObject?] = [
    MyObject(firstName: "piet", lastName: "mozilla"),
    MyObject(firstName: "jol", lastName: " godzilla"),
    MyObject(firstName: "", lastName: "Anubis"),
    MyObject(firstName: "paul", lastName: ""),
    MyObject(firstName: "", lastName: "Strawberry"),
    nil,
    MyObject(firstName: "jol", lastName: "zwordfish"),
    MyObject(firstName: "jol", lastName: ""),
    MyObject(firstName: "", lastName: "Zwordfish"),
    nil,
    MyObject(firstName: "pot", lastName: "IronFly")
]


extension Array {  
    mutating func rearrange(from: Int, to: Int) {
        insert(remove(at: from), at: to)
    }
}

extension String
{   
    func trim() -> String
    {
        return self.trimmingCharacters(in: .whitespaces)
    }
}

let arrayWithNoNils = objectArray.flatMap { [=12=] } // to remove the 'nil's

let indexedArray = arrayWithNoNils.map({ [=12=].lastName.prefix(1) }) // get the first character

var indexArr : Array = Set(indexedArray).sorted() as Array // make it unique and sort

if indexArr.count > 0 && indexArr[0] == "" { // move the empty one as last
    let cnt = indexArr.count - 1
    indexArr.rearrange(from: 0, to: cnt)
}

对 Trim 有任何帮助吗？我以为我可以在

旁边使用它

arrayWithNoNils.map({ [=13=].lastName.prefix(1) })

类似

arrayWithNoNils.map({ [=14=].lastName.trim.prefix(1) })

对此有什么建议吗？

一如既往的谢谢。

Answer 1

这是您要找的吗？

let fixedArray = objectArray.map({ (object) -> MyObject? in
    guard let existedObject = object else { return nil }
    return MyObject(firstName: existedObject.firstName, lastName: existedObject.lastName.trimmingCharacters(in: .whitespacesAndNewlines))
})

Answer 2

这将通过使用 compactMap 删除 nil 对象并 trim 并获取姓氏的第一个字符来为您提供索引数组。然后将其转换为 Set 以删除重复项，并最终在闭包确保 "" 排在最后的位置进行排序

let indexArray = Set(objectArray
    .compactMap { [=10=]?.lastName.trimmingCharacters(in: .whitespaces).prefix(1).uppercased()})
    .sorted(by: {
        if [=10=].isEmpty {
            return false
        }
        if .isEmpty {
            return true
        }
        return [=10=] < 
    })

Answer 3

您可以尝试以下方法：

let firstLetters = objectArray.map { item -> String in
    guard let item = item else { return "" }
    return String(item.lastName.trim().prefix(1)).uppercased()
}

let indexArray = Array(Dictionary(grouping: firstLetters, by: { [=10=] }).keys)
    .sorted {
        if [=10=] == "" { return false }
        if  == "" { return true }
        return [=10=] < 
    }

print(indexArray) // ["A", "G", "I", "M", "S", "Z", ""]

Answer 4

找到了，

该行应该变成

let indexedArray = arrayWithNoNils.map({ (([=10=].lastName.trim)().uppercased()).prefix(1)

Swift - Trim 并映射数组中的第一个字母

Swift - Trim and map the first letter from a Array

indexing

dictionary

flatmap