What is nullable in Objective-C?
nullable: Indicates that the pointer can be nil in general practice. Imported into Swift as an optional value (NSURL?). https://stackoverflow.com/questions/33232944/can-we-create-nullable-nonnull-property-in-objective-c/33235569#33235569.
How does Objective-C handle null values?
The NULL value for Objective-C objects (type id) is nil. While NULL is used for C pointers (type void *). (In the end both end up holding the same value (0x0).
Does Objective-C have optionals?
It is common in Objective-C to return nil for an object reference where in Swift you would use an optional type. Unfortunately there is nothing in the Objective-C code that tells the compiler which references can be nil so it assumes the worst and makes everything an implicitly unwrapped optional.
How do I check if a string is null in Objective-C?
If you treat it is a null string like nil , then test (object. length == 0) . object. length will return 0 if object == nil , so this test covers nil objects and strings with length 0.
Is Objective-C obsolete?
Programming in Objective-C will not become obsolete any time soon because, thanks to its 20 years of existence, it has a large code base, a number of apps maintained, and third-party framework with Objective-C at its core. These solutions and libraries are unlikely to be rebuilt from scratch with a new language.
Why is Objective-C still used?
The main reason to still use Objective-C is the for free integration with a C++ business layer.
What is NSMutableArray Objective-C?
The NSMutableArray class declares the programmatic interface to objects that manage a modifiable array of objects. This class adds insertion and deletion operations to the basic array-handling behavior inherited from NSArray . NSMutableArray is “toll-free bridged” with its Core Foundation counterpart, CFMutableArray .
Is Objective CA low level language?
Objective-C is both a high-level language and a low-level language. It is essentially a cross between C and Smalltalk . The language, created by Brad Cox and Tom Love in 1984, was directly inspired by Smalltalk.