Copy property on Objective-C.md

Copy property on Objective-C

CustomObject.h

#import <Foundation/Foundation.h>

@interface CustomObject : NSObject <NSCopying>

@end

CustomObject.m

#import "CustomObject.h"

@implementation CustomObject

- (instancetype)copyWithZone:(NSZone *)zone {
    CustomObject *copy = [[[self class] allocWithZone:zone] init];
    return copy;
}

@end

Model.h

#import <Foundation/Foundation.h>
#import "CustomObject.h"

@interface Model : NSObject

@property (nonatomic, readwrite, copy) CustomObject *object;
@property (nonatomic, readwrite, copy) NSArray *array;
@property (nonatomic, readwrite, copy) NSMutableArray *mutableArray;

@end

Model.m

#import "Model.h"

@implementation Model

- (instancetype)init {
    self = [super init];
    if (self) {
        _object = [CustomObject new];
        _array = [[NSArray alloc] initWithObjects:@"foo", @"bar", nil];
        _mutableArray = [[NSMutableArray alloc] initWithObjects:@"foo", @"bar", nil];
    }
    return self;
}
@end