Question

两个数组

let array1 = ["A","B","C","D","E","F","G"]

let array2 = ["a","b","c","d","e","f","g"]

我想从array2中选择一个索引，并用与array2中的对象相同的索引替换array1中的对象。例如

array1[3] = array2[3] //["A","B","C","d","E","F","G"]

例如，我想随机执行

let randomIndex: Int = Int(arc4random()) % (array2.count)

我想在“ for”循环中执行此操作，直到使用了array2的所有索引和对象为止，但是我不想重复randomIndex。

如果每次迭代后减少对象数，我仍然可以获得相同的随机索引。如果我使用一组索引，然后删除使用的索引，我将失去“有序性”（如果这是一个词）。

所以我似乎被困住了。顺便说一句swift 4的.randomElement不适用于字符串数组。

有什么想法吗？

for object in array2 {

  let randomIndex: Int = Int(arc4random()) % (array2.count)
  array1[randomIndex] = array2[randomIndex]
  array2.remove(at: randomIndex)
  }

以上内容无法按我的期望进行。删除对象后，将建立新的顺序，并且无法在适当的索引处替换array1中的对象。

我缺少明显的东西，但是我没有看到。我正在使用Swift 4.2。

Answer 1

这似乎效率很低，但是可以起作用：

let array1 = ["A","B","C","D","E","F","G"]
let array2 = ["a","b","c","d","e","f","g"]
var array3 = array1                       // ["A","B","C","D","E","F","G"]
var counterSet = Set<Int>()               // empty set

while counterSet.count < array2.count {
  let randomIndex: Int = Int(arc4random()) % (array2.count)    //(16 times)
  counterSet.insert(randomIndex)                               //(16 times)
  array3[randomIndex] = array2[randomIndex]                    //(16 times)
}
counterSet                                // {2, 4, 6, 5, 0, 1, 3}
array3                                    // ["a", "b", "c", "d", "e", "f", "g"]

我仍然想要一些输入。谢谢库尔特

Answer 2

您需要改组索引吗？如果是这样，则下面的代码可以执行此操作。

( 0 ..< array2.count ).shuffled()

或

Array( stride( from: 0, through: array2.count - 1, by: 1 ) ).shuffled()

Answer 3

     var array1  = ["A","B","C","D","E","F","G"]

     var array2  = ["a","b","c","d","e","f","g"]

    let randomIndex: Int = Int(arc4random()) % (array2.count)
    print("Number:\(randomIndex)")

    array2.insert(array1[randomIndex], at: randomIndex)
    print("array2:\(array2)")

将一个数组中的对象随机替换为另一个数组。迅捷4

3 个答案: