Getting error on the below code as
Binary operator '==' cannot be applied to operands of type '[String]?' and 'String'
func loadDefaults() {
let userDefaults = UserDefaults.standard.object(forKey: "storedArray") as? [String]
if (userDefaults == "") || userDefaults != nil{
persons = userDefaults!
}else{
persons = [""]
}
}
First of all there is a dedicated method array(forKey to retrieve an array.
An empty array isEmpty, you cannot compare it with an empty String
If you want to load the stored array or assign an empty array if the object can't be found use
func loadDefaults() {
// a variable name userDefaults for the array is confusing
if let storedArray = UserDefaults.standard.array(forKey: "storedArray") as? [String] {
persons = storedArray
} else {
persons = []
}
}
or shorter
func loadDefaults() {
persons = UserDefaults.standard.array(forKey: "storedArray") as? [String] ?? []
}
In your code userDefaults is of type [String]? and not String to be be campared to "". Binary operator == can only be used between two instances of the same type (This type has to adopt the Equatable protocol to use ==).
You may use this snippet to check that userDefaults is not nil :
if let defaults = userDefaults {
persons = defaults
} else {
persons = [""]
}
Or with the guard statement :
guard let defaults = userDefaults else {
persons = [""]
return
}
persons = defaults
Your final function would look like this:
func loadDefaults() {
let userDefaults = UserDefaults.standard.object(forKey: "storedArray") as? [String]
if let defaults = userDefaults {
persons = defaults
} else {
persons = [""]
}
}
Or :
func loadDefaults() {
let userDefaults = UserDefaults.standard.object(forKey: "storedArray") as? [String]
guard let defaults = userDefaults else {
persons = [""]
return
}
persons = defaults
}
P.S: persons = [""] means that the persons would contain one element, that is "". If you want an empty array use this: persons = []
