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Question

與NSMutableArray的工作，我有一個字符串的NSMutableArray skippedArray。

skipped Array = ["string1","string2","string3","string4"]; 

我想將索引0處的字符串分配給UILabel。

我試圖lblQuestion.text = skippedArray[j] as! String ，但在這條線的應用程序崩潰。

誰能幫助？

Answer 1

定義的NSMutableArray這樣的：

let skippedArray = ["string1","string2","string3","string4"]; 
lblQuestion.text = skippedArray.first 

或者您也可能是這樣的代碼：

let skippedArray : NSMutableArray =   ["string1","string2","string3","string4"]; 
lblQuestion.text = skippedArray.firstObject as! String 

還有另一種方法這樣抓取的NSMutableArray的對象：

let skippedArray : NSMutableArray = ["string1","string2","string3","string4"]; 
let j = 0; 
lblQuestion.text = skippedArray.object(at: j) as! String 

Answer 2

定義你的變量數組或乾脆[字符串]或只是讓定義其定義如下：

var skippedArray: Array<String> = ["string1","string2","string3","string4"] 

或

var skippedArray: [String] = ["string1","string2","string3","string4"] 

或

var skippedArray = ["string1","string2","string3","string4"] 

Answer 3

首先，定義可變數組正確，如

前面提到的

var skippedArray = ["string1","string2","string3","string4"] 

其次，定義您的索引，你稱之爲 「J」 與您的字符串

let j = 0 

三，設置標籤文本，從字符串數組

lblQuestion.text = skippedArray[j]