Swift: How to sort an Array<String> [duplicate] - arrays

Question

This question already has an answer here:
Swift: sorting of array is not done correctly
(1 answer)
Closed 7 years ago.
I have an Array containing values like 7-4.json, 87-1.json and 102-4.json and want to sort it (ascending). I used the following code:
var fileNames = ["7-4.json", "87-1.json", "102-4.json"]
fileNames = fileNames.sort{ $0 < $1 }
print(fileNames)
which results in:
["102-4.json", "7-4.json", "87-1.json"]
So it didn't worked as I aspected. How can I sort it like 7-4, 87-1, 102-4?

Answer 1

Here you go:
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)
The function sortWithCustomFormat has a function extract that takes the inputted string and extracts the first and second numbers from it. Then, you compare the first numbers. If they are equal, then you compare the second numbers.

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

Try this...
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"]