如何遍历 Swift 中的对象数组？

Question

我有对象

var person1 = Person()
person1.name = "Joe"
person1.lastName = "Doe"
person1.age = 21

var person2 = Person()
person2.name = "Julia"
person2.lastName = "Ivanova"
person2.age = 22

var person3 = Person()
person3.name = "Irina"
person3.lastName = "Petrova"
person3.age = 25

var person9 = Person()
person9.name = "Vova"
person9.lastName = "Vovin"
person9.age = 32

var person10 = Person()
person10.name = "Masha"
person10.lastName = "Golovanova"
person10.age = 20

var person11 = Person()
person11.name = "Petra"
person11.lastName = "Andreeva"
person11.age = 27

和多数组

var array = [[person1, person2, person3], [person9, person10, person11]]

如何遍历数组以获取例如 name="Masha" 的人

提前致谢

Answer 1

我会试试这个：

var array:[[Person]] = [[person1, person2, person3], [person9, person10, person11]]
/*Casting it like this should keep from getting an error later 
   and/or having to recast the objects*/

for people in array {

/*This is going to look at each array in arrays, 
   and call each one 'people' within this loop*/

    for person in people {

    /*Same thing, this is going to look at each item in the people array
       and call each one 'person' within this loop*/

        if person.name == "Masha" {
            return person
        }
    }
}

Answer 2

可以像@Rachel 的回答那样进行迭代。然而，有不同的方法可以做同样的事情，不一定是通过迭代——在某些情况下只需要一行代码。

如果你想找到，那么最好的方法是使用数组的filter 方法——但在此之前，多维数组应该被展平，使用flatMap。

因此，要找到具有特定名称的第一个元素，您可以简单地执行以下操作：

let result: Person? = array.flatMap { $0 }.filter { $0.name == "Masha" }.first

Answer 3

解决这个问题的一个有趣方法是利用 Swift 的 flatMap 函数。

var array = [[person1, person2, person3], [person9, person10, person11]]

let flatArray = array.flatMap { $0 }

flatArray 现在是 [person1, person2, person3, person9, person10, person11] 类型为 Array<Person>。

然后你可以在 flatArray 上迭代来找到你想要的：

for person in flatArray {
    if person.name == "Masha" {
        // Do something
    }
}

您甚至可以使用 Swift 2.0 更进一步，因为它允许您在 for 中放置 where 子句：

for person in flatArray where person.name == "Masha" {
    // Do something
}

Answer 4

这是一种叫做“链式”的技术

游乐场。 斯威夫特 3.1

import UIKit

class Person {
    var name = ""
    var lastName = ""
    var age = 0
}

var person1 = Person()
person1.name = "Joe"
person1.lastName = "Doe"
person1.age = 21

var person2 = Person()
person2.name = "Julia"
person2.lastName = "Ivanova"
person2.age = 22

var person3 = Person()
person3.name = "Irina"
person3.lastName = "Petrova"
person3.age = 25

var person9 = Person()
person9.name = "Vova"
person9.lastName = "Vovin"
person9.age = 32

var person10 = Person()
person10.name = "Masha"
person10.lastName = "Golovanova"
person10.age = 20

var person11 = Person()
person11.name = "Petra"
person11.lastName = "Andreeva"
person11.age = 27

var array = [[person1, person2, person3], [person9, person10, person11]]

array
    .flatMap{$0}
    .forEach { (anyPerson:Person) in

        if anyPerson.name == "Masha" {
            //Do what you need
            print(anyPerson.lastName)
        }
}

游乐场的屏幕截图：

Answer 5

斯威夫特 3：

forEach({ element in
  // do what you need
})

Answer 6

这是一种非常简单的方法来满足您的需求：

let result = array
    .flatMap { $0 }
    .first(where: { $0.name == "Masha" })

首先，您必须使数组变平，然后您可以从数组中获取满足给定谓词的第一个元素（在我们的例子中，name 等于 "Masha"）。