Read Only Properties in Objective-C

TestClass.h

#import <Foundation/Foundation.h>

@interface TestClass : NSObject

@property (nonatomic, readonly) NSString *propertyA;
@property (nonatomic, readonly) NSString *propertyB;
@property (nonatomic, readonly, getter = propertyC) NSString *propertyC;

@end

TestClass.m

#import "TestClass.h"

@interface TestClass ()
@property (nonatomic, readwrite) NSString *propertyB;
@end

@implementation TestClass

- (id)init
{
    if (self = [super init])
    {
        _propertyA = @"value"; // Can't do self.propertyA = @"value"; as propertyA is readonly
        
        _propertyB = @"value";
        self.propertyB = @"value"; // self.propertyB = @"value"; will work as we synthesize propertyB in private category as read write
    }
    
    return self;
}

- (NSString *)propertyC
{
    return @"value";
}

@end