-1
這是我的代碼:爲什麼遞增值顯示我「()」?
var pictureVersion = snapshotValuesOnline?["PictureVersion"] as! String
print("downloaded: \(pictureVersion)")
var pictureVersionInt = Int(pictureVersion)!
print("toInt : \(pictureVersionInt)")
var pictureInt = pictureVersionInt += 1
print("plusOne : \(pictureInt)")
var pictureIntToString = "\(pictureInt)"
print("toString : \(pictureIntToString)")
這是我的輸出:
downloaded: 3
toInt : 3
plusOne :()
toString :()
我在做什麼錯在這裏?
'pictureInt'是'Void',因爲'+ ='是一個'inout'函數修改'pictureVersionInt'。 – JAL
爲什麼你使用'+ ='?爲什麼不簡單'讓pictureInt = pictureVersionInt + 1'? –