如何设置变量的值（字符串）等于在数组中的键？ [英] How to set a variable's value (string) to be equal to a key in an array?

问题描述

我有以下数组：

  VAR deckArray = [
        卡1：[等级，西服]，
        卡2：等级，西服]，
        card3：等级，西服]，
        card4：等级，西服]，
        card5：等级，西服]，
        CARD6：等级，西服]，
        card7：等级，西服]，
]
 

我夹住阵列出于简洁的其余部分，而是整个东西包含52的对象。我想要做的就是选择一个随机数从1到52，并设置 firstCardString 属性等于任何键对应的数组中的索引。

例如，如果它产生的随机数 5 ，它会设置 firstCardString 等于 card5 。

我试图做到这一点，像这样：

 让firstRandomNumber = INT（arc4random_uniform（52））
让firstCardString：字符串= self.deckArray [firstRandomNumber]
 

但我发现了以下错误：

  

无法下标类型的值'[字符串：数组]与类型的索引，诠释

这是没有意义的，因为 firstCardString：字符串是明确类型的字符串，不是int <。 / p>

解决方案

您已经声明的deckArray作为解释。所以，你需要传递一个String（键）不是int

 让firstRandomNumber = INT（arc4random_uniform（52））+ 1
让firstCardString = deckArray [牌\\（firstRandomNumber）]
 

I have the following array:

var deckArray = [
        "card1": ["rank","suit"],
        "card2": ["rank","suit"],
        "card3": ["rank","suit"],
        "card4": ["rank","suit"],
        "card5": ["rank","suit"],
        "card6": ["rank","suit"],
        "card7": ["rank","suit"],
]

I clipped the rest of the array for brevity, but the entire thing contains 52 objects. What I want to do is pick a random number from 1 to 52, and set the firstCardString property to be equal to whichever key corresponds to that index in the array.

For example, if the random number it generates is 5, it would set firstCardString to be equal to card5.

I've tried to do it like so:

let firstRandomNumber = Int(arc4random_uniform(52))
let firstCardString:String = self.deckArray[firstRandomNumber]

But I'm getting the following error:

Cannot subscript a value of type '[String : Array]' with an index of type 'Int'

This doesn't make sense, because firstCardString:string is explicitly of type string, not int.

解决方案

You have declared your deckArray as a Dictionary. So you need to pass a String (key) not an Int

let firstRandomNumber = Int(arc4random_uniform(52))+1
let firstCardString = deckArray["card\(firstRandomNumber)"]

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