符合协议

Created: November-22, 2018

你可以向标准类添加协议以扩展其功能：

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

@interface NSDictionary (XYZExtended) <EncodableToString>
@end

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

XYZ 你的项目的前缀