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:str

Answer 1

if str == nil, no call are performed because there is no object allocated to receive the message but no exception are raised (messages sent to nil return nil by design in Objective-C).

NSMutableString *str, *str1;

str = [NSMutableString stringWithString:@"Hello "];
str1 = [NSMutableString stringWithString:@"World"]; 

NSMutableString *sayit = [str appendString:str1];