Objective-C, a combination of C
and Smalltalk
languages, is an object-oriented language used by Apple for iOS and OS X.
Swift is a completely new, high-level programming language designed by Apple a few years ago for its operating systems. The language has been growing ever since.
Objective-C: It is highly stable, as it has been tested for years. So, it will not develop or change much more.
Swift: It is less stable, as compared to Objective-C, due to constant improvements. It is still growing.
Objective-C: It is more prone to memory leaks.
Swift: It has better memory management with no memory leaks, as it is
Objective-C: It is verbose and lengthy. It requires many more lines of code.
Swift: It is concise, with fewer lines of code required for similar commands. Its syntax is basic and simple.
Objective-C: As it uses runtime code compilation, its performance is slow.
Swift: It is a lot faster and gives high performance (almost as fast as C++) when compared to Objective-C. It was named Swift for a reason.
Objective-C: The syntax is harder to learn. It utilizes symbols and parentheses and takes longer to understand.
Swift: Its simpler syntax makes it easier to read, write and learn. It has English-like simple coding.
Objective-C: It requires two files to maintain code with manual synchronization of method names and comments.
Swift: It is based on a single file of code, which is easier to maintain.
Objective-C: It is harder to develop interactive apps.
Swift: It allows development of interactive apps and encourages interactive coding.
Objective-C: It uses static libraries and has no support for any dynamic libraries.
Swift: It supports dynamic libraries, which keep apps updated, reduce file size, and speed up overall performance.
Objective-C: It has slow compilers.
Swift: It has low level virtual machine LLVM compilers that are faster and smarter.
Objective-C: It has precise and complete documentation regarding each instruction, method, or error.
Swift: Its documentation still has margin of improvement and is constantly updated and growing.
Objective-C: It has null pointers that introduce NOPs, increasing complexity of error and bug handling.
Swift: It has quick fixes and bug recognition.