符合協議

Created: November-22, 2018

你可以向標準類新增協議以擴充套件其功能：

@protocol EncodableToString <NSObject>
- (NSString *)toString;
@end

@interface NSDictionary (XYZExtended) <EncodableToString>
@end

@implementation NSDictionary (XYZExtended)
- (NSString *)toString {
    return self.description;
}
@end

XYZ 你的專案的字首