Conversion of IOS nsdictionary, nsdata, and JSON Data Types

Conversion of IOS nsdictionary, nsdata, and JSON Data Types

Conversion of data types is often used in IOS. The following lists conversions of common types.

1. nsdictionary type to nsdata type:

//NSDictionary -> NSData:NSDictionary *params = [NSDictionary dictionaryWithObjectsAndKeys:                                @"balance", @"key",                               @"remaining balance", @"label",                                @"45", @"value",                                @"USD", @"currencyCode",nil];         NSMutableData *data = [[NSMutableData alloc] init];NSKeyedArchiver *archiver = [[NSKeyedArchiver alloc] initForWritingWithMutableData:data];[archiver encodeObject:params forKey:@"Some Key Value"];[archiver finishEncoding];

2. nsdata type conversion to nsdictionary type:

//NSData -> NSDictionaryNSData *data = [[NSMutableData alloc] initWithContentsOfFile:[self dataFilePath]];NSKeyedUnarchiver *unarchiver = [[NSKeyedUnarchiver alloc] initForReadingWithData:data];NSDictionary *myDictionary = [[unarchiver decodeObjectForKey:@"Some Key Value"] retain];[unarchiver finishDecoding];[unarchiver release];[data release];

3. Convert the nsdictionary type to the JSON data type:

//NSDictionary -> JSON:NSString *jsonStr=[dict JSONRepresentation];

Note: the conversion of JSON and nsdictionary types usually uses the JSON library published by a third party. You can find many types of data on the Internet.