First launch of iOS app

Question

I want to show the welcome screen when the user first opens my application. What is the way to test the first application launch in Swift?

Answer 1

Swift 4 and above

func isAppAlreadyLaunchedOnce()->Bool{
    let defaults = UserDefaults.standard
    if let _ = defaults.string(forKey: "isAppAlreadyLaunchedOnce"){
        print("App already launched")
        return true
    }else{
        defaults.set(true, forKey: "isAppAlreadyLaunchedOnce")
        print("App launched first time")
        return false
    }
}

Note. This method returns falseafter the user reinstalls the application and launches it for the first time.

Answer 2

Try this for Swift 2 and below.

func isAppAlreadyLaunchedOnce()->Bool{
    let defaults = NSUserDefaults.standardUserDefaults()

    if let isAppAlreadyLaunchedOnce = defaults.stringForKey("isAppAlreadyLaunchedOnce"){
        println("App already launched")
        return true
    }else{
        defaults.setBool(true, forKey: "isAppAlreadyLaunchedOnce")
        println("App launched first time")
        return false
    }
}

Answer 3

Since NSUserDefaults for the application are erased when the application is uninstalled, you can try to test for a certain value when the application starts.

If this value exists, the application is already installed. If not, this is the first time the application starts, and you set this value.

Answer 4

SWIFT:

let launchedBefore = UserDefaults.standard.bool(forKey: "launchedBefore")
if launchedBefore  {
    print("Not first launch.")
} else {
    print("First launch, setting UserDefault.")
    UserDefaults.standard.set(true, forKey: "launchedBefore")
}

GOAL - WITH:

if ([[NSUserDefaults standardUserDefaults] boolForKey:@"isAppAlreadyLaunchedOnce"])
{
    return true;
}
else
{
    [[NSUserDefaults standardUserDefaults] setBool:YES forKey:@"isAppAlreadyLaunchedOnce"];
    [[NSUserDefaults standardUserDefaults] synchronize];
    return false;
}