Check if my IOS application is updated

Question

I need to check when my app launches if it was being updated, because i need to make a view that only appears when the app is firstly installed to appear again after being

Answer 1

swift version with an important improvement over the accepted answer:

• using infoDictionary instead of objectForInfoDictionaryKey guaranties that the result is independent from device language, otherwise you may end up in some rare cases believing that there is an upgrade when in reality it is just a device language change
• using a UserDefaults key identical to the main Bundle infoDictionary for clarity on what is exactly stored
• factoring setting currentVersion code
• Swift 3 syntax

Code:

    let standardUserDefaults = UserDefaults.standard
    let shortVersionKey = "CFBundleShortVersionString"
    let currentVersion = Bundle.main.infoDictionary![shortVersionKey] as! String
    let previousVersion = standardUserDefaults.object(forKey: shortVersionKey) as? String
    if previousVersion == currentVersion {
        // same version
    } else {
        // replace with `if let previousVersion = previousVersion {` if you need the exact value
        if previousVersion != nil {
            // new version
        } else {
            // first launch
        }
        standardUserDefaults.set(currentVersion, forKey: shortVersionKey)
        standardUserDefaults.synchronize()
    }