What are the differences between Objective-C and Swift programming languages?

Objective-C is a programming language based on C with added object-oriented features through Smalltalk-like message syntax. Swift is a more modern language from Apple, designed to simplify and enhance code safety.

Main differences:

• Syntax: Swift has a cleaner, more concise, and more understandable syntax, while Objective-C uses a more verbose syntax with square brackets for method calls.
• Safety: Swift includes strict typing, optionals for handling nil, and runtime error protection.
• Performance: Swift is compiled into more optimized code, often resulting in better performance.
• Compatibility: Objective-C is closely integrated with C and C++, which is useful for supporting legacy code.
• Memory management: Objective-C uses ARC, but Swift additionally supports automatic memory management with optionals and value types.

Example of calling a method in Objective-C and Swift:

// Objective-C
NSString *greeting = [NSString stringWithFormat:@"Hello, %@!", name];

// Swift
let greeting = "Hello, \(name)!"