arrays - 数组如何通过 Swift 按多个属性排序？

Question

我想按数字值对数组数据进行排序，例如“90 > 80 > 70 ...> 10”。
但是我不知道如何比较多个属性。

struct Item {
   let number1: Double
   let number2: Double
   let number3: Double
}

let item1 = Item(number1:0, number2:0, number3:10)
let item2 = Item(number1:20, number2:0, number3:0)
let item3 = Item(number1:0, number2:30, number3:0)
let item4 = Item(number1:0, number2:0, number3:40)
let item5 = Item(number1:0, number2:50, number3:0)
let item6 = Item(number1:60, number2:0, number3:0)
let item7 = Item(number1:0, number2:70, number3:0)
let item8 = Item(number1:0, number2:0, number3:80)
let item9 = Item(number1:0, number2:90, number3:0)

var array:[Item] = [item1, item2, item3, item4, item5, item6, item7, item8, item9]

array = array.sorted { (item, nextItem) -> Bool in {
     item.number3 < nextItem.number3 //how to add item's number2 & number1 into here.
}

Answer 1

根据3个数字的总和对元素进行排序

array = array.sorted { (item, nextItem) -> Bool in
    let itemSum = item.number1 + item.number2 + item.number3
    let nextItemSum = nextItem.number1 + nextItem.number2 + nextItem.number3
    return itemSum > nextItemSum
}

[Item(number1: 0.0, number2: 90.0, number3: 0.0),
Item(number1: 0.0, number2: 0.0, number3: 80.0),
Item(number1: 0.0, number2: 70.0, number3: 0.0),
Item(number1: 60.0, number2: 0.0, number3: 0.0),
Item(number1: 0.0, number2: 50.0, number3: 0.0),
Item(number1: 0.0, number2: 0.0, number3: 40.0),
Item(number1: 0.0, number2: 30.0, number3: 0.0),
Item(number1: 20.0, number2: 0.0, number3: 0.0),
Item(number1: 0.0, number2: 0.0, number3: 10.0)]