nsdictionary简写与文件操作

[NSDictionary dictionaryWithObjectsAndKeys:@"Jack", @"name", @"男", @"sex", nil];
//现在
@{@"name" : @"Jack", @"sex" : @"男"};

[dict objectForKey:@"name"];
//现在
dict[@"name"];

//写入文件
- (BOOL)writeToFile:(NSString *)path atomically:(BOOL)useAuxiliaryFile;
- (BOOL)writeToURL:(NSURL *)url atomically:(BOOL)atomically;
//从文件中读取
+ (NSDictionary *)dictionaryWithContentsOfFile:(NSString *)path;
+ (NSDictionary *)dictionaryWithContentsOfURL:(NSURL *)url;
- (NSDictionary *)initWithContentsOfFile:(NSString *)path;
- (NSDictionary *)initWithContentsOfURL:(NSURL *)url;