iphone - How to append a NSMutableString with a NSMutableString?

Question

NSMutableString *str, *str1;

//allocation here

i am using [str appendString:str1] is not working. [str appendFormat:str1] is not working.

So, how to append a NSMutableString with another NSMutableString.

@str is an empty string initialize to nil. str1 has some value. [str appendString str1] returns null

Answer 1

Seems like your're sending a message to nil. nil is NOT an object, it's just nothing. Sending a message to nothing just return nothing. In order to append these strings, you need to initialize to an empty string. Like so:

NSMutableString *str = [NSMutableString string];

Then your code will work. Like so:

[str appendString:str1];