swift UserDefaults返回零作爲NSMutableArray

Question

我有多行文本，我將它們保存爲UserDefaults。當我想要文本有時返回零。但是裏面有一段文字。我該怎麼做，零不返回？

var savedReports: NSMutableArray = NSMutableArray() 

    if let sR = defaults.object(forKey: "savedReports") as? NSMutableArray { 
     savedReports = sR.mutableCopy() as! NSMutableArray 
    } 

Answer 1

UserDefaults API將始終返回不可變數組。你想：

var savedReports: NSMutableArray = NSMutableArray() 

if let sR = defaults.object(forKey: "savedReports") as? NSArray { 
    savedReports = sR.mutableCopy() 
}