我想从一个给定的数组中随机选择一个KanjiCard结构项，将属性“kanji”添加到另一个临时数组并执行检查，如果随机选择的结构。kanji存在于yetShowedArray中，重复随机选择，直到找到一个结构，其中kanji不存在于yetShowedArray中，以便使用它
实际的重复/while流并不确保其发生。

//test for the not repeating run *************************************************************************************
        
        //check if the two array have the same number of items
        guard arrayToUse.count !=  yetShowedArray.count else {
            print("finished all the kanji")
            var matching = 0
            for element in arrayToUse {
                if yetShowedArray.contains(element.kanji!){
                    matching += 1
                }
            }
            print("matching kanji are : \(matching)")
            return
        }
        
        var random = Int(arc4random_uniform(UInt32(arrayToUse.count)))
        //Instance
        kanjiToShow = arrayToUse[random]
        guard let kanjiToTrack = kanjiToShow.kanji else {
            print("kanjiToTrack is nil!!!")
            return
        }
        
        
        if yetShowedArray.contains(kanjiToTrack){
            print("contained")
            repeat {
                random = Int(arc4random_uniform(UInt32(arrayToUse.count)))
                kanjiToShow = arrayToUse[random]
            } while yetShowedArray.contains(kanjiToTrack)
            print("refreshed random")
        }
        else {
            print("never used before")
        }
        
        yetShowedArray.append(kanjiToTrack)
        print(yetShowedArray)
        print("arrayToUse: \(arrayToUse.count) yetShowedArray: \(yetShowedArray.count)")
        
        //test for the not repeating run *************************************************************************************

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在安东·诺沃肖洛夫回答
我将let kanjiToTrack更改为var，然后在repeat循环中刷新它

//Instance
        kanjiToShow = arrayToUse[random]
        guard var kanjiToTrack = kanjiToShow.kanji else {
            print("kanjiToTrack is nil!!!")
            return
        }
        
        
        if yetShowedArray.contains(kanjiToTrack){
            print("contained")
            repeat {
                random = Int(arc4random_uniform(UInt32(arrayToUse.count)))
                kanjiToShow = arrayToUse[random]
                kanjiToTrack = kanjiToShow.kanji!
                
                
            } while yetShowedArray.contains(kanjiToTrack)
            
            print("refreshed random")
        }
        else {
            print("never used before")
        }

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第二溶液

let random = Int(arc4random_uniform(UInt32(arrayToUse.count)))
    //Instance
    kanjiToShow = arrayToUse[random]
    guard kanjiToShow.kanji != nil else {
        print("kanjiToTrack is nil!!!")
        return
    }
    
    arrayToUse.remove(at: random)

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