Question

我希望我的结构首先按字母顺序打印其条目，然后按降序排列数据。所以最终结果将是：“lukes 9”，“lukes 4”，“smiths 4”

struct MyData {
    var company = String()
    var score: Int
}

let data = [
    MyData(company: "smiths", score: 4 ),
    MyData(company: "lukes", score: 4),
    MyData(company: "lukes", score: 9)
]

Answer 1

有两种方法可以做到这一点。两者都要求你将数组传递给sort（Swift 2），现在是sorted（Swift 3）。

一个非常简单的实现：

struct MyData {
    var company = String()
    var score: Int
}

let data = [
    MyData(company: "smiths", score: 4),
    MyData(company: "lukes", score: 4),
    MyData(company: "lukes", score: 9)
]

let sortedArray = data.sorted(by: { ($0.company, $1.score) < ($1.company, $0.score) })

您还可以MyData符合Comparable。这使比较逻辑保持在MyData类型中，您只需运行sorted()函数即可返回一个新数组：

struct MyData {
    var company = String()
    var score: Int
}

extension MyData: Equatable {
    static func ==(lhs: MyData, rhs: MyData) -> Bool {
        return (lhs.company, lhs.score) == (rhs.company, rhs.score)
    }
}

extension MyData: Comparable {
     static func <(lhs: MyData, rhs: MyData) -> Bool {
        return (rhs.company, lhs.score) > (lhs.company, rhs.score)
    }
}  

let data = [
    MyData(company: "smiths", score: 4),
    MyData(company: "lukes", score: 4),
    MyData(company: "lukes", score: 9)
]

let sortedArray = data.sorted()

这两个实现都输出了你想要的结果：＆＃34; lukes 9＆＃34;，＆＃34; lukes 4＆＃34;，＆＃34; smiths 4＆＃34;

在struct中按字母顺序和降序打印数组

1 个答案: