xcode 使用空项目在 Swift Ascending 中对数组进行排序
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Sort array in Swift Ascending with empty items
提问by B_s
In Xcode (Swift) I have an array that is initialized to 100 empty items:
在 Xcode (Swift) 中，我有一个初始化为 100 个空项的数组：
var persons = [String](count:100, repeatedValue: "")
With some functions I add content to the places in the array, starting at 0.
使用一些函数，我将内容添加到数组中的位置，从 0 开始。
So for example my array is at some given moment:
例如，我的数组在某个特定时刻：
["Bert", "Daniel", "Claire", "Aaron", "", "", ... ""]
With the dots representing the rest of the empty items. I use this function for sorting my array alphabetically:
点代表其余的空项目。我使用此函数按字母顺序对数组进行排序：
persons = persons.sorted {["", "", ... , "Aaron", "Bert", "Claire", "Daniel"]
.localizedCaseInsensitiveCompare() == NSComparisonResult.OrderedAscending }
This gives me an array back like this:
这给了我一个这样的数组：
["Aaron", "Bert", "Claire", "Daniel", "", "", ... , ""]
What I want is to sort my array alphabetically but not with the empty items at the front. I need to get an array back like:
我想要的是按字母顺序对我的数组进行排序，而不是前面的空项。我需要取回一个数组，如：
let personSet = NSMutableSet()
personSet.addObject("Aaron")
personSet.addObject("Daniel")
personSet.addObject("Claire")
personSet.addObject("Aaron")
personSet.addObject("Bert")
personSet.addObject("Bert")
personSet.addObject("Joe")
personSet.removeObject("Joe") // You can remove too of course
For my part, I do not want an array with empty items but I found I couldn't add a value to my array if I did not declare like a 100 items (the array won't be filled to a 100 items, that's for sure).
就我而言，我不想要一个包含空项目的数组，但我发现如果我没有像 100 个项目那样声明我就无法向我的数组添加值（该数组不会被填充为 100 个项目，这是为了当然）。
Can anyone help me out?
谁能帮我吗？
回答by Mike S
As @Antonio said, it looks like you need a descending order setof strings. Besides the Dictionarymethod in @Antonio's answer (which works great), you can also use NSMutableSet(bridged from Objective-C):
作为@Antonio说，它看起来像你需要一个降序组串。除了Dictionary@Antonio 的答案中的方法（效果很好），您还可以使用NSMutableSet（从 Objective-C 桥接）：
{(
Claire,
Aaron,
Daniel,
Bert
)}
Which creates the set:
创建集合：
personSet.allObjects as [String]
Then, when you want the people as an Array, you can use the allObjectscast to a [String]:
然后，当您希望人们成为 时Array，您可以使用allObjects强制转换为[String]：
let people = (personSet.allObjects as [String]).sort {[Aaron, Bert, Claire, Daniel]
.localizedCaseInsensitiveCompare() == NSComparisonResult.OrderedAscending }
And you can sort it just like you're currently doing:
您可以像当前一样对其进行排序：
var persons = ["Bert", "Daniel", "Claire", "Aaron", "", "", ""]
persons.sort { (a, b) -> Bool in
if a.isEmpty {
return false
} else if b.isEmpty {
return true
} else {
return a.localizedCaseInsensitiveCompare(b) == .OrderedAscending
}
}
Which makes people:
这使得people：
["Aaron", "Bert", "Claire", "Daniel", "", "", ""]
For those wondering how to sort the Arrayas originally stated in the question (Ascending but with empty strings at the end), that can be done with a little bit of custom logic in the sort function:
对于那些想知道如何按照Array问题中最初陈述的方式（升序但最后是空字符串）进行排序的人，可以通过排序函数中的一些自定义逻辑来完成：
var persons = [String : Bool]()
persons["Bert"] = true
persons["Daniel"] = true
persons["Clair"] = true
persons["Clair"] = true
persons["Aaron"] = true
persons["Daniel"] = true
persons["Clair"] = true
Result:
结果：
var values = persons.keys.array
回答by Antonio
Reading comments in your question and other answers, I realize that you need a ordered set, containing unique values. There's no built in data structure in swift for that, but it can be easily be done by using a dictionary: simply use the string value as dictionary key, and a boolean as dictionary value - this ensures that keys are unique:
阅读您的问题和其他答案中的评论，我意识到您需要一个包含唯一值的有序集合。swift 中没有内置的数据结构，但可以通过使用字典轻松完成：只需使用字符串值作为字典键，并使用布尔值作为字典值 - 这确保键是唯一的：
values.sort { persons = persons
.filter( { var persons = [String]()
var inputData = ["Bert", "Daniel", "Bert", "Claire", "Aaron"]
for item in inputData {
var found = false
for existing in persons {
if existing == item {
found = true
break
}
}
if (!found) {
persons.append(item)
}
}
persons.sort{##代码##.localizedCaseInsensitiveCompare() == NSComparisonResult.OrderedAscending }
println(persons)
.isEmpty == false } )
.sorted {##代码##.localizedCaseInsensitiveCompare() == NSComparisonResult.OrderedAscending }
.localizedCaseInsensitiveCompare() == NSComparisonResult.OrderedAscending }
You can quickly verify that with the above code the dictionary contains 4 elements only.
您可以使用上述代码快速验证字典仅包含 4 个元素。
Next, obtain a copy of the dictionary keys (as an array):
接下来，获取字典键的副本（作为数组）：
##代码##and sort it:
并排序：
##代码##Alternatively, if you want to stick with the fixed sized array, you can remove the empty items before sorting:
或者，如果您想坚持使用固定大小的数组，您可以在排序之前删除空项目：
##代码##回答by CuriousRabbit
I think you are confused about arrays. Swift arrays are not statically allocated structures which must be allocated and filled to maximum design capacity. Below is a crude example of how you can accomplish most of what you are expressing here. However, I really think that a dictionary is better suited to your needs.
我认为您对数组感到困惑。Swift 数组不是静态分配的结构，必须分配和填充到最大设计容量。下面是一个粗略的例子，说明如何完成你在这里表达的大部分内容。但是，我真的认为字典更适合您的需求。
##代码##