How to know what Mac OS the app is running on?

Question

I\'ve seen in some projects something like:

#if .....
    code...
#endif

but i can\'t find it now...
Let\'s say, for example, if the ap

Answer 1

As Steven Fisher said, you should not check for the system version but for the availability of the class or method you want to use.

The check if a specific class is available use

if ([NSHologram class]) {
   // Create an instance of the class and use it.
} else {
   // The Hologram class is not available.
}

To check if a specific method is available use

NSString* hologramText = @"Hologram";
if ([hologramText respondsToSelector:@selector(convertHologram)]) {
    [hologramText convertHologram];
}

Yet for the method checking, the method must be available on the system where you build your app, or else you will get a compile error.