Objective-C to Swift Converter
Modernize legacy iOS and macOS applications by converting Objective-C to Swift with AI-powered transformation. Converts verbose square bracket syntax [object message] to concise dot notation, eliminates separate .h/.m files for single Swift modules, and transforms nil checks to type-safe optionals with ? and !. Handles UIViewController subclasses to modern Swift patterns, Objective-C protocols to Swift protocols, and manual memory management to automatic ARC—enabling gradual Swift adoption while maintaining Objective-C interoperability.
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Issue Description
Hint: Describe what you want to build or paste requirements, select target language, and click Generate.
How It Works
- Step 1: Paste your Objective-C source code including @interface/@implementation declarations, square bracket method calls, property definitions, and protocol conformance.
- Step 2: The AI analyzes Objective-C patterns identifying message passing syntax for dot notation, pointer types for optionals, and manual memory management for automatic ARC.
- Step 3: Advanced transformation generates Swift code with class definitions, type-safe optionals, guard/if-let unwrapping, and modern Swift idioms replacing Objective-C conventions.
- Step 4: Download production-ready Swift code compatible with the latest iOS/macOS SDKs, SwiftUI integration, and Combine reactive programming—while maintaining Objective-C bridging headers for gradual migration.
Objective-C vs Swift: iOS Development Comparison
| Feature | Objective-C | Swift |
|---|---|---|
| Syntax | Verbose square brackets | Concise dot notation |
| Null Safety | nil with manual checks | Optionals (?) with unwrapping |
| Memory Management | Manual retain/release or ARC | Automatic ARC |
| Type Safety | Dynamic typing, id type | Strong static typing |
| File Structure | .h and .m files | Single .swift file |
Code Conversion Examples
Example 1: Classes and Methods
// Person.h
@interface Person : NSObject
@property (nonatomic, strong) NSString *name;
@property (nonatomic, assign) NSInteger age;
- (instancetype)initWithName:(NSString *)name age:(NSInteger)age;
- (void)celebrateBirthday;
- (NSString *)description;
@end
// Person.m
@implementation Person
- (instancetype)initWithName:(NSString *)name age:(NSInteger)age {
self = [super init];
if (self) {
_name = name;
_age = age;
}
return self;
}
- (void)celebrateBirthday {
self.age++;
NSLog(@"%@ is now %ld years old", self.name, (long)self.age);
}
- (NSString *)description {
return [NSString stringWithFormat:@"Person: %@, Age: %ld",
self.name, (long)self.age];
}
@end
// Usage
Person *person = [[Person alloc] initWithName:@"Alice" age:30];
[person celebrateBirthday];// Person.swift (single file, no header needed)
class Person: NSObject {
var name: String
var age: Int
init(name: String, age: Int) {
self.name = name
self.age = age
super.init()
}
func celebrateBirthday() {
age += 1
print("(name) is now (age) years old")
}
override var description: String {
return "Person: (name), Age: (age)"
}
}
// Usage
let person = Person(name: "Alice", age: 30)
person.celebrateBirthday()Key Changes:
Objective-C's separate .h and .m files merge into a single Swift file. @interface/@implementation declarations become a single class definition. Property declarations with (nonatomic, strong) attributes become simple 'var' declarations—Swift handles memory management automatically. Designated initializers with verbose syntax simplify to clean init methods. Square bracket method calls [person celebrateBirthday] become dot notation person.celebrateBirthday(). NSLog with format strings converts to Swift's string interpolation. Alloc/init patterns reduce to direct initialization.
Example 2: Optionals and Nil Handling
// Objective-C
@interface UserManager : NSObject
- (User *)findUserWithID:(NSString *)userID;
- (void)updateUser:(User *)user;
@end
@implementation UserManager {
NSMutableDictionary *users;
}
- (instancetype)init {
self = [super init];
if (self) {
users = [[NSMutableDictionary alloc] init];
}
return self;
}
- (User *)findUserWithID:(NSString *)userID {
if (userID == nil) {
return nil;
}
User *user = [users objectForKey:userID];
return user; // May return nil
}
- (void)updateUser:(User *)user {
if (user != nil && user.userID != nil) {
[users setObject:user forKey:user.userID];
NSLog(@"Updated user: %@", user.name ?: @"Unknown");
}
}
@end
// Usage
UserManager *manager = [[UserManager alloc] init];
User *user = [manager findUserWithID:@"123"];
if (user != nil) {
NSLog(@"Found user: %@", user.name);
}// Swift
class UserManager {
private var users: [String: User] = [:]
func findUser(withID userID: String?) -> User? {
guard let userID = userID else {
return nil
}
return users[userID]
}
func updateUser(_ user: User?) {
guard let user = user, let userID = user.userID else {
return
}
users[userID] = user
print("Updated user: (user.name ?? "Unknown")")
}
}
// Usage
let manager = UserManager()
if let user = manager.findUser(withID: "123") {
print("Found user: (user.name)")
}Key Changes:
Objective-C's nil pointers convert to Swift's type-safe optionals (User?). Manual nil checks (if user != nil) become guard-let or if-let unwrapping patterns. NSMutableDictionary converts to Swift's native Dictionary type with type parameters. The objectForKey: method becomes simple bracket access with optional return. Objective-C's ?: ternary operator for nil coalescing becomes Swift's ?? operator. Property access after nil checks becomes safe through optional chaining. The verbose alloc/init pattern disappears entirely—Swift's type system prevents nil-related crashes at compile time.
Frequently Asked Questions
How is Objective-C syntax converted to Swift?
Objective-C's verbose syntax becomes Swift's concise syntax. Square bracket method calls [obj method] become dot notation obj.method(), @interface/@implementation become class definitions, and header files merge into single Swift files.
What happens to Objective-C pointers?
Objective-C pointers convert to Swift references or optionals. Strong pointers become regular references, weak pointers become weak var, and nil pointers become Swift optionals (Type?). Manual retain/release is eliminated by Swift's ARC.
Can it modernize legacy iOS apps?
Yes! The converter helps modernize Objective-C iOS apps to Swift. Classes, view controllers, and business logic convert to Swift syntax, enabling gradual migration while maintaining compatibility through Swift-Obj-C bridging.