按字母顺序和降序打印结构中的数组 [英] print array in struct in alphabetical order and in descending order

问题描述

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.所以最终的结果是:lukes 9"、lukes 4"、smiths 4"

I would like my struct to print its entries in alphabetical order first, then arrange the data in descending order. So the final result would be: "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)
]

推荐答案

有两种方法可以做到这一点.两者都需要您将数组传递给 sort (Swift 2)，现在是 sorted (Swift 3).

There's 2 ways you can do this. Both would require you to pass your array to sort (Swift 2), now sorted (Swift 3).

1. 一个非常简单的实现:

1. A very easy implementation:

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) })

您还可以使 MyData 符合 Comparable.这将比较逻辑保留在 MyData 类型中，您只需运行 sorted() 函数即可返回一个新数组:

You could also make MyData conform to Comparable. This keeps the comparison logic within the MyData type, and you can just run the sorted() function to return a new array:

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()

这两个实现都输出你想要的结果:lukes 9"、lukes 4"、smiths 4"

These 2 implementations both output your desired result: "lukes 9", "lukes 4", "smiths 4"

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