Swift: sort array with alternative comparison

问题

I'd like to sort my swift struct array using another comparison method (like localizedCompare, caseInsensitiveCompare or localizedCaseInsensitiveCompare). The swift standard string array sort function orders all uppercase letters before lowercase letters. Here's my code:

import Foundation

struct DataStruct {

    struct Item {
        let title: String
        let number: Int
    }

        static var items = [
        Item(title: "apple", number: 30),
        Item(title: "Berry", number: 9),
        Item(title: "apple", number: 18)]
}

class DataFunctions {
    func sortItemsArrayTitle() {
        DataStruct.items.sort { $0.title < $1.title }
    }
}

Once called, the above code results in [Berry, apple, apple]. Unacceptable. Any suggestions?

回答1:

You can easily solve it by comparing the title lowercaseString as follow:

DataStruct.items.sort { $0.title.lowercaseString < $1.title.lowercaseString }

using localizedCompare it should look like this:

DataStruct.items.sort { $0.title.localizedCompare($1.title) == .OrderedAscending } 

来源：https://stackoverflow.com/questions/30418553/swift-sort-array-with-alternative-comparison