swift：更改数组的内容给我一个错误答案

【问题标题】：swift :changing the content of an array gives me an errorswift：更改数组的内容给我一个错误
【发布时间】：2016-06-29 00:34:33
【问题描述】：

我有这个数组：

var array = [[12,46,["a","b","c"],"nil",true,7,true],[10,40,["c","d","e"],"nil",true,7,true],[0,1,["z","l","w"],"hey",false,7,true]].

当我尝试通过此代码更改数组布尔值的最后一个布尔值时：

array[0][6] = false

我收到此错误“无法通过下标分配下标是 get-only 数组”

【问题讨论】：

标签： arrays xcode swift

【解决方案1】：

有趣。我认为编译器在某个地方出错了。您只需检查数组的类型即可了解原因：

var array = [
    [12,46,["a","b","c"],"nil",true,7,true],
    [10,40,["c","d","e"],"nil",true,7,true],
    [0,1,["z","l","w"],"hey",false,7,true]
]

print(array.dynamicType) // Array<NSArray>
                         // can't assign to the inner array since NSArray is immutable

给 Swift 一个内部类型的提示，它可以工作

var array: [[AnyObject]] = [
    [12,46,["a","b","c"],"nil",true,7,true],
    [10,40,["c","d","e"],"nil",true,7,true],
    [0,1,["z","l","w"],"hey",false,7,true]
]

array[0][6] = false     // works

【讨论】：

不知为何Swift编译器默认为非Swift原生类型NSArray？

【解决方案2】：

您应该改用元组数组。编写更好的代码，性能更好，并且不依赖于 Objective-C：

var array = [
    (12,46,["a","b","c"],"nil",true,7,true),
    (10,40,["c","d","e"],"nil",true,7,true),
    (0,1,["z","l","w"],"hey",false,7,true)
]

// Array has type [(Int, Int, [String], String, Bool, Int, Bool)]

array[0].6 = false

【讨论】：

这阐明了程序员的意图，特别是因为外部数组的所有条目都具有相同的结构（Int、Int、[String]、String、Bool、Int , Bool)。