// NSData NSDate NSString NSArray NSDictionary json

NSString *string = @"hello word";

NSData *data = [string dataUsingEncoding:NSUTF8StringEncoding];

NSArray *array = [NSArray arrayWithObjects:@"1",@"2",@"3",nil];

NSString *dateString = @"19891123";

NSDictionary *dic = [NSDictionary dictionaryWithObjectsAndKeys:

@"hello", @"word",

@"chen", @"lu",

@"jin", @"mei",

@"cerastes", @"hehe",nil];

// NSString to NSData

NSData *string2data = [string dataUsingEncoding:NSUTF8StringEncoding];

NSLog(@"%@",string2data);

// NSData to NSString

NSString *data2String = [[NSString alloc]initWithData:data encoding:NSUTF8StringEncoding];

NSLog(@"dataString = %@",data2String);

// NSArray to NSData

NSData *arry2data = [NSKeyedArchiver archivedDataWithRootObject:array];

// NSData to NSArray

NSArray *data2arry = [NSKeyedUnarchiver unarchiveObjectWithData:arry2data];

NSLog(@"%@ /n %@",arry2data,data2arry);

// NSString to NSDate

NSDate *string2date = [self convertDateFromString:dateString withFormattre:@"yyyyMMdd"];

NSLog(@"date = %@",string2date);

// NSDate to NSString

NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];

[dateFormatter setDateFormat:@"yyyy-MM-dd HH:mm:ss"];

NSString *date2string = [dateFormatter stringFromDate:[NSDate date]];

NSLog(@"%@", date2string);

// NSArray to NSString

NSString *arry2String = [array componentsJoinedByString:@" "];

NSLog(@"string = %@",arry2String);

// NSString to NSArray

NSArray *string2Arry = [arry2String componentsSeparatedByString:@" "];

NSLog(@" %@",string2Arry);

// NSDictionary to NSData:

NSMutableData *dic2data = [[NSMutableData alloc] init];

NSKeyedArchiver *archiver = [[NSKeyedArchiver alloc] initForWritingWithMutableData:dic2data];

[archiver encodeObject:dic forKey:@"Some Key Value"];

[archiver finishEncoding];

NSLog(@"%@",dic2data);

// NSData to NSDictionary

NSKeyedUnarchiver *unarchiver = [[NSKeyedUnarchiver alloc] initForReadingWithData:dic2data];

NSDictionary *data2dic = [unarchiver decodeObjectForKey:@"Some Key Value"];

[unarchiver finishDecoding];

NSLog(@"%@",data2dic);

// NSDictionary to NSString

NSString *dic2string=[dic JSONRepresentation]; //这种方法是SBJson类库里的。须要导入SBJson.h

NSLog(@"%@",dic2string);

// NSString to NSDictionary

NSError *error = nil;

NSDictionary *string2dic = [NSJSONSerialization JSONObjectWithData: [dic2string dataUsingEncoding:NSUTF8StringEncoding]

options: NSJSONReadingMutableContainers

error: &error];

NSLog(@"%@",string2dic);

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