converting NSString to NSData - [NSString dataUsingEncoding] exception

Question

I was converting NSString to NSData in order to parse by JSON, but I got the following error.

Terminating app due to uncaught exception 'NSInvalidArgumentException', 
  reason: '-  [__NSCFDictionary dataUsingEncoding:]: 
  unrecognized   selector sent to instance 0x7987d60'

The code is as followings:

NSData *data = [str dataUsingEncoding:NSASCIIStringEncoding]; 
//NSUTF8StringEncoding also failed.
NSDictionary *dict = [NSJSONSerialization JSONObjectWithData:data options:kNilOptions error:&error];

In my opinion, this is because str contains new-line character:'\n'.

Am I correct?

Would somebody please help me to solve this problem?

Solution 1

Your error says that you are trying to send dataUsingEncoding:allowLossyConversion: to an instance of NSDictionary, which doesn't know what to do with that selector. Make sure your str object is actually a string...

Solution 2

Try using NSUnicodeStringEncoding instead of NSASCIIStringEncoding. So replace the line:

NSData *data = [str dataUsingEncoding:NSASCIIStringEncoding]; 

with this:

NSData *data = [str dataUsingEncoding:NSUnicodeStringEncoding]; 

Comments

[Jun]

You're right. It was my mistake. str object is actually NSDictionary as this error says:[__NSCFDictionary dataUsingEncoding:]

[Parth Bhatt]

This is not a proper answer. You need to add more detail to your answer.

[Taimur Ajmal]

@Harry How did you solve it. Can you please mention. Thanks a lot.

[Pankaj Bhardwaj]

@TaimurAjmal You just ned to change your dictionary object in string like this - NSString* json = [NSString stringWithFormat:@"%@", responseObject]; and then use this their will be no exception