How to check iOS version?

Question

I want to check if the iOS version of the device is greater than 3.1.3 I tried things like:

[[UIDevice currentDevice].systemVersion         


        

Answer 1

This is used to check for compatible SDK version in Xcode, this is if you have a large team with different versions of Xcode or multiple projects supporting different SDKs that share the same code:

#if __IPHONE_OS_VERSION_MAX_ALLOWED >= 80000
  //programming in iOS 8+ SDK here
#else
  //programming in lower than iOS 8 here   
#endif

What you really want is to check the iOS version on the device. You can do that with this:

if ([[[UIDevice currentDevice] systemVersion] floatValue] < 8.0) {
  //older than iOS 8 code here
} else {
  //iOS 8 specific code here
}

Swift version:

if let version = Float(UIDevice.current.systemVersion), version < 9.3 {
    //add lower than 9.3 code here
} else {
    //add 9.3 and above code here
}

Current versions of swift should be using this:

if #available(iOS 12, *) {
    //iOS 12 specific code here
} else {
    //older than iOS 12 code here
}