Swift:如何对Array<String>排序

Question

我有一个Array，其中包含7-4.json、87-1.json和102-4.json等值，并希望对其进行排序(升序)。我使用了以下代码：

var fileNames = ["7-4.json", "87-1.json", "102-4.json"]
fileNames = fileNames.sort{ $0 < $1 }
print(fileNames)

其结果是：

["102-4.json", "7-4.json", "87-1.json"]

所以不像我所想的那样起作用了。我怎么能把它分类成7-4，87-1,102-4？

Answer 1

给你：

var fileNames = ["7-4.json", "87-1.json", "102-4.json"]

func sortWithCustomFormat(first: String, second: String) -> Bool{
    func extract(value: String) -> (Int, Int){
        return (Int(value.componentsSeparatedByString("-").first!)!, Int(value.componentsSeparatedByString("-").last!.componentsSeparatedByString(".").first!)!)
    }
    let firstNumber = extract(first)
    let secondNumber = extract(second)
    if firstNumber.0 != secondNumber.0 { return firstNumber.0 < secondNumber.0 }
    return firstNumber.1 < secondNumber.1
}

fileNames.sort(sortWithCustomFormat)

函数sortWithCustomFormat有一个函数extract，它接受输入的字符串并从中提取第一和第二数字。然后，你比较第一个数字。如果它们相等，那么比较第二个数字。

Answer 2

var fileNames = ["87-1.json", "7-4.json", "87-3.json", "102-4.json"]
fileNames = fileNames.sort({ (s1, s2) -> Bool in

    let f1 = s1.stringByReplacingOccurrencesOfString(".json", withString: "")
    let f2 = s2.stringByReplacingOccurrencesOfString(".json", withString: "")

    let arr1 = f1.componentsSeparatedByString("-")
    let arr2 = f2.componentsSeparatedByString("-")


    var int1 = Int(arr1[0])
    var int2 = Int(arr2[0])

    if int1 < int2 {
        return true
    }
    else if int1 > int2 {
        return false
    }
    else {
        int1 = Int(arr1[1])
        int2 = Int(arr2[1])
        if int1 < int2 {
            return true
        }
        else if int1 > int2 {
            return false
        }
        else {
            return true
        }
    }
});
print(fileNames)

Answer 3

试试这个..。

var fileNames = ["87-1.json", "7-4.json", "102-4.json"] 
// Modded OP's order to actually test sort
var sorted = fileNames.sort{ $0 < $1 }
print(sorted) // ["102-4.json", "7-4.json", "87-1.json"]
// Not sorted as OP "required", as they are string sorted, not number sorted

// Very simplistic solution
sorted = fileNames.sort { ($0 as NSString).integerValue < ($1 as NSString).integerValue}
print(sorted) // As OP requires, but...

// It won't sort on his count field - add a failing case...
fileNames = ["7-4.json", "87-1.json", "102-4.json", "102-1.json"]
sorted = fileNames.sort { ($0 as NSString).integerValue < ($1 as NSString).integerValue}
print(sorted) // ["7-4.json", "87-1.json", "102-4.json", "102-1.son"]
// WRONG!

// Define a simple function that parses his strings into tuples.
// This assumes that the Strings are valid, and fails safe if not.
// If you want more validation, add it yourself!
func myParse(s: String) -> (Int, Int) {
    let c = s.componentsSeparatedByCharactersInSet(NSCharacterSet(charactersInString: "-."))
    switch c.count {
    case 0:
        print("Careful Will Robinson!")
        return (0, 0)
    case 1:
        print("Careful Will Robinson!")
        return ((c[0] as NSString).integerValue, 0)
    default:
        return ((c[0] as NSString).integerValue, (c[1] as NSString).integerValue)
    }
}

let test = fileNames.map { myParse($0) }
print("\(test)") // Test execution of function

sorted = fileNames.sort { (s1: String, s2: String) -> Bool in
    let t1 = myParse(s1)
    let t2 = myParse(s2)
    if t1.0 == t2.0 {
        return t1.1 < t2.1
    } else {
        return t1.0 < t2.0
    }
}
print(sorted) // As required ["7-4.json", "87-1.json", "102-1.json", "102-4.json"]