Setting global variables with UserDefaults

Question

I'm relatively new into this and tried a little bit of code, but encountered a problem.

In my App I have a global variable which keeps track wether a user chose his username already or not. Once he has picked his name I want to set this variable permanently to true so I can disable the segue which leads to the Username ViewController.

But I can't preset the variable since the code would re-initialize the variable everytime I re-open the app. And I still got my problems setting it up with UserDefaults.

I hope I was able to explain my problem more or less.

It is hard to help without any code, can you please show the code you used and where to get/set the UserDefaults? — Popmedic
– Popmedic, Commented May 31, 2018 at 20:40

marc_s · Accepted Answer · 2020-05-12 20:35:08Z

1

Set a bool value to userDefault

UserDefaults.standard.setBool(true, forKey: "is_userName")

And retrieve the value for checking

if UserDefaults.standard.bool(forKey: "is_userName") {
      // User have created username 
} else {
      // Go to set username screen
}

edited May 12, 2020 at 20:35

marc_s

760k186 gold badges1.4k silver badges1.5k bronze badges

answered May 31, 2018 at 20:44

Ajay saini

2,4701 gold badge14 silver badges27 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

Hyung Duc Da Over a year ago

Makes sense now! Thanks!

Andy Ibanez · Accepted Answer · 2018-05-31 21:42:17Z

0

UserDefaults getters will return nil if it is not set, so you don't need to set a bool, just check if the value has been set like so:

if let username = UserDefaults.standard.string(forKey:"username") {
    // user has created username, and username has the unwrapped value in it
} else {
    // go to set username screen
}

Make sure that after they go to the set username screen you set the username key in the UserDefaults:

UserDefaults.standard.string(value, forKey:"username")

Where value is the value they entered.

If you want to reset a value in the UserDefaults (i.e. they log out) use the removeObject function:

UserDefaults.standard.removeObject(forKey:"username")

That will make it so UserDefaults.standard.string(forKey:"username") will return nil again.

Adding a bool for checking will just make one more cog that can screw it all up if you forget to set it...

edited May 31, 2018 at 21:42

Andy Ibanez

12.3k9 gold badges68 silver badges104 bronze badges

answered May 31, 2018 at 20:51

Popmedic

1,9011 gold badge19 silver badges21 bronze badges

1 Comment

Hyung Duc Da Over a year ago

Awesome! Thanks for this, exactly what I searched for :)

Collectives™ on Stack Overflow

Setting global variables with UserDefaults

2 Answers 2

1 Comment

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

1 Comment

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related