How to Check iOS Version

How to check iOS version?

The quick answer …



As of Swift 2.0, you can use #available in an if or guard to protect code that should only be run on certain systems.

if #available(iOS 9, *) {}






In Objective-C, you need to check the system version and perform a comparison.

[[NSProcessInfo processInfo] operatingSystemVersion] in iOS 8 and above.

As of Xcode 9:

if (@available(iOS 9, *)) {}


The full answer …

In Objective-C, and Swift in rare cases, it's better to avoid relying on the operating system version as an indication of device or OS capabilities. There is usually a more reliable method of checking whether a particular feature or class is available.

Checking for the presence of APIs:

For example, you can check if UIPopoverController is available on the current device using NSClassFromString:

if (NSClassFromString(@"UIPopoverController")) {
// Do something
}

For weakly linked classes, it is safe to message the class, directly. Notably, this works for frameworks that aren't explicitly linked as "Required". For missing classes, the expression evaluates to nil, failing the condition:

if ([LAContext class]) {
// Do something
}

Some classes, like CLLocationManager and UIDevice, provide methods to check device capabilities:

if ([CLLocationManager headingAvailable]) {
// Do something
}

Checking for the presence of symbols:

Very occasionally, you must check for the presence of a constant. This came up in iOS 8 with the introduction of UIApplicationOpenSettingsURLString, used to load Settings app via -openURL:. The value didn't exist prior to iOS 8. Passing nil to this API will crash, so you must take care to verify the existence of the constant first:

if (&UIApplicationOpenSettingsURLString != NULL) {
[[UIApplication sharedApplication] openURL:[NSURL URLWithString:UIApplicationOpenSettingsURLString]];
}

Comparing against the operating system version:

Let's assume you're faced with the relatively rare need to check the operating system version. For projects targeting iOS 8 and above, NSProcessInfo includes a method for performing version comparisons with less chance of error:

- (BOOL)isOperatingSystemAtLeastVersion:(NSOperatingSystemVersion)version

Projects targeting older systems can use systemVersion on UIDevice. Apple uses it in their GLSprite sample code.

// A system version of 3.1 or greater is required to use CADisplayLink. The NSTimer
// class is used as fallback when it isn't available.
NSString *reqSysVer = @"3.1";
NSString *currSysVer = [[UIDevice currentDevice] systemVersion];
if ([currSysVer compare:reqSysVer options:NSNumericSearch] != NSOrderedAscending) {
displayLinkSupported = TRUE;
}

If for whatever reason you decide that systemVersion is what you want, make sure to treat it as an string or you risk truncating the patch revision number (eg. 3.1.2 -> 3.1).

Check OS version in Swift?

For iOS, try:

var systemVersion = UIDevice.current.systemVersion

For OS X, try:

var systemVersion = NSProcessInfo.processInfo().operatingSystemVersion

If you just want to check if the users is running at least a specific version, you can also use the following Swift 2 feature which works on iOS and OS X:

if #available(iOS 9.0, *) {
// use the feature only available in iOS 9
// for ex. UIStackView
} else {
// or use some work around
}

BUT it is not recommended to check the OS version. It is better to check if the feature you want to use is available on the device than comparing version numbers.
For iOS, as mentioned above, you should check if it responds to a selector;
eg.:

if (self.respondsToSelector(Selector("showViewController"))) {
self.showViewController(vc, sender: self)
} else {
// some work around
}

How do you check/change iOS version in React Native?

Use Xcode to change an iOS project's target target iOS version. XCode > Project Navigator > "General" tab > Deployment Info > Target. You will the "ios/Quevera.xcodeproj/project.pbxproj" file will now have an entry like "IPHONEOS_DEPLOYMENT_TARGET = 11.0;".

How can I determine the latest iOS version programmatically using Swift?

Apple provides an API at curl http://ax.phobos.apple.com.edgesuite.net/WebObjects/MZStore.woa/wa/com.apple.jingle.appserver.client.MZITunesClientCheck/version. Test it on the command line using:

curl http://ax.phobos.apple.com.edgesuite.net/WebObjects/MZStore.woa/wa/com.apple.jingle.appserver.client.MZITunesClientCheck/version

The response is XML, and the information you need is keyed by device version (eg iPhone8,1).

You can access your device's version by using sysctlbyname() from Swift.

Update Looks like the old URL (http://phobos.apple.com./version) died a while back (thanks Troy) so have updated my answer with another version. I have no idea if the content is the same.



Related Topics



Leave a reply



Submit